| options | N62B36 | N62B40 | N62B44 | N62B48O1(TU) |
| Design | V8 | |||
| V angle | 90° | |||
| Volume, cc | 3600 | 4000 | 4398 | 4799 |
| Cylinder diameter / piston stroke, mm | 84/81,2 | 84,1/87 | 92/82,7 | 93/88,3 |
| Distance between cylinders, mm | 98 | |||
| ∅ crankshaft main bearing, mm | 70 | |||
| ∅ crankshaft connecting rod bearing, mm | 54 | |||
| Power, hp (kW) / rpm | 272 (200)/6200 | 306 (225)/6300 | 320 (235)/6100 333 (245)/6100 |
355 (261)/6300 360 (265)/6200 367 (270)/6300 |
| Torque, Nm/rpm | 360/3300 | 390/3500 | 440/3700 450/3100 |
475/3400 490/3400 500/3600 |
| Max RPM | 6500 | |||
| Compression ratio | 10,2 | 10,0 | 10,0 | 10,5 |
| Valves per cylinder | 4 | |||
| ∅ inlet valves, mm | 32 | — | 35 | 35 |
| ∅ exhaust valves, mm | 29 | — | 29 | 29 |
| Inlet valve stroke, mm | 0,3-9,85 | 0,3-9,85 | 0,3-9,85 | 0,3-9,85 |
| Exhaust valve stroke, mm | 9,7 | 9,7 | 9,7 | 9,7 |
| Camshaft valve opening time intake/exhaust (crankshaft °) |
282/254 | 282/254 | 282/254 | 282/254 |
| Engine weight, ∼ kg | 148 | 158 | 158 | 140 |
| Estimated fuel (ROZ) | 98 | |||
| Fuel (ROZ) | 91-98 | |||
| The order of operation of the cylinders | 1-5-4-8-6-3-7-2 | |||
| Knock control system | Yes | |||
| Variable geometry intake system | Yes | |||
| DME system | ME9.2 + Valvetronic ECU (since 2005 ME9.2.2-3) | |||
| Exhaust gas compliance | EU-3, EU-4, LEV | |||
| Engine length, mm | 704 | |||
| Savings compared to M62 | 13% | — | 14% | — |
How Valvetronic works
The principle of operation of Valvetronic can be compared with the behavior of the human body during physical exertion. Let's say you're jogging. The amount of air inhaled is regulated by the lungs. Breathing becomes deep, and the lungs take in the amount of air that the body needs to convert energy. If you move from running to calm walking, then the energy costs of the body will decrease, and it will need less air. Automatically, breathing becomes shallower. If you suddenly cover your mouth with a towel now, it will become much more difficult to breathe.
Applied to the intake of outside air in the presence of Valvetronic, it can be said that there is a "missing towel" (i.e. throttle valve). The stroke of the valves (lungs) is adjusted according to the need for air. The engine can "breathe freely".
The technical rationale is shown in the pv diagram below.
P - pressure; OT - Top Dead Center; UT - bottom dead center; EÖ - The intake valve opens; ES - Inlet valve closes; AÖ - Exhaust valve opens; AS - Exhaust valve closes; Z - Ignition moment; 1 - Effective power; 2 - The power of the compression stroke;
The upper area "Gain" is the power obtained from the combustion of fuel. The lower area "Losses" is the work spent on gas exchange processes. This is the energy that is spent pushing the exhaust gases out of the cylinder and sucking a new portion of gases into the cylinder.
In the intake of a Valvetronic engine, the throttle valve is almost always opened so wide that only a very slight vacuum (50 mbar) is created. The load is controlled by the closing time of the valves. Unlike conventional engines, where the load is controlled by a throttle valve, there is almost no vacuum in the intake system, which means that no energy is required to create this vacuum.
Higher efficiency is achieved by reducing losses in the suction process.
The previous figure on the left shows a traditional process with more significant losses.
The figure on the right shows a reduction in losses.
Unlike the diesel engine, in a conventional positive ignition engine, the amount of intake air is controlled by the accelerator pedal and throttle valve, and the corresponding amount of fuel is injected in a stoichiometric ratio (λ=1).
For engines with Valvetronic, the amount of air taken in is determined by the stroke and duration of the valve opening. When supplying the exact amount of fuel, the mode λ=1 is also realized here.
In contrast, a gasoline engine with direct injection and stratified mixture formation in a wide range of loads operates on a leaner fuel-air mixture.
Therefore, with engines with Valvetronic, there is no need for costly aftertreatment of the exhaust gas, which also does not allow a high sulfur content in the fuel, as is the case with gasoline engines with direct injection.
Engine structure
The mechanical part of the BMW N62 engine
Front view of the N62 engine: 1 - Valvetronic electric motors; 2 - Fuel tank ventilation valve (activated carbon filter valve); 3 - Solenoid valve of the VANOS system; 4 - Generator; 5 - Coolant pump pulley; 6 - Thermostat housing; 7 - Throttle valve assembly; 8 - Vacuum pump; 9 - Suction pipe of the air filter;
Rear view of the N62 engine: 1 - Camshaft position sensor, cylinder bank 5-8; 2 - Valvetronic eccentric shaft position sensor, a number of cylinders 5-8; 3 - Valvetronic eccentric shaft position sensor, a number of cylinders 1-4; 4 - Camshaft position sensor, a number of cylinders 1-4; 5 - Additional air valves; 6 - E / engine for adjusting the intake system with variable geometry;
General information about the intake system
The increase in engine power and torque, as well as the optimization of the nature of the change in torque, largely depend on how optimal the filling ratio of the engine cylinders is in the entire range of crankshaft speed.
A good filling ratio of the cylinders in the upper and lower speed ranges is achieved by changing the length of the intake tract. The long intake tract leads to good filling of the cylinders in the low and medium ranges.
This allows you to optimize the nature of the change in torque and increase the torque.
To increase power in the upper speed range, the engine requires a short intake tract for better filling.
The intake system has been thoroughly redesigned in order to resolve the contradiction that the intake tract under different conditions should have a different length.
The intake system consists of the following units:
- suction pipe in front of the air filter;
- air filter;
- suction pipe with HFM (thermal anemometric air mass meter);
- throttle valve;
- intake system with variable geometry;
- inlet channels;
Air supply system
Outdoor air supply system
The intake air enters through the intake pipe to the air filter, then to the throttle assembly, and then through the variable geometry intake system to the intake ports of both cylinder heads.
The installation location of the suction pipe was chosen in accordance with the standards for the depth of the ford to be overcome, namely, in the engine compartment from above. The depth of the ford to be overcome is, taking into account the speed:
- 150 mm at 30 km/h
- 300 mm at 14 km/h
- 450 mm at 7 km/h
The filter element is designed to be replaced every 100,000 km.
N62 engine air supply system: 1 - Suction pipe; 2 - Air filter housing with suction silencer; 3 - Suction pipe with HFM (thermal anemometric air flow meter); 4 - Additional air valves; 5 - Additional air blower;
throttle valve
The throttle valve fitted to the N62 engine is not used to control engine load. Load control is carried out by adjusting the stroke of the intake valves. The tasks of the throttle valve are as follows:
- support for optimal engine start
- ensuring a constant negative pressure of 50 mbar in the suction pipe in all load ranges
Variable turbine suction pipe
The body of the intake system with variable geometry engine N62: 1 - Drive unit; 2 - Threaded hole for the engine cover; 3 - Fitting for crankcase ventilation; 4 - Fitting for ventilation of the fuel tank; 5 - Intake air; 6 - Holes for nozzles; 7 - Threaded hole for the distribution line;
The intake system is located between the rows of engine cylinders and is attached to the intake channels of the cylinder heads.
The body of the intake system with variable geometry is made of magnesium alloy.
View of the intake system with variable geometry of the H62 motor from the inside: 1 - Inlet channel; 2 - Funnel; 3 - Rotor; 4 - Shaft; 5 - Cylindrical gears; 6 - Collector volume;
Each cylinder has its own inlet port (1) which is connected via a rotor (3) to the manifold volume (6).
One rotor for each row of cylinders is placed on one shaft (4).
The drive unit (electric motor with gearbox) regulates the shaft of the rotors of cylinder bank 1-4 depending on the speed.
The second shaft, which regulates the rotors of the opposite row of cylinders, rotates in the opposite direction, driven by the first shaft through a gear train (5).
The intake air passes through the volume of the collector and through the funnels (2) enters the cylinders. The rotation of the rotors regulates the length of the intake tracts.
The drive motor is controlled by the DME. To confirm the position of the funnels, it is equipped with a potentiometer.
The length of the intake tract is continuously adjustable depending on the engine speed. The intake tracts begin to decrease at 3500 rpm and continue to decrease linearly with increasing speed up to 6200 rpm.
Engine ventilation system
1-4 - Holes for spark plugs; 5 - Pressure control valve; 6 - Hole for the Valvetronic electric motor; 7 - Hole for the Valvetronic sensor connector; 8 - Camshaft position sensor;
The exhaust gases generated in the crankcase during combustion (Blow-by-Gase) are discharged into a labyrinth oil separator in the cylinder head cover.
The oil that settles on the walls of the oil separator flows through the oil siphons into the cylinder head, and from there back into the oil sump. The remaining gases are directed through the pressure control valve (5) to the intake system for combustion.
Both cylinder head covers are fitted with one labyrinth oil separator with a pressure control valve.
The throttle valve is adjusted in such a way that there is always a vacuum of 50 mbar in the intake system to remove gases.
The pressure control valve sets the vacuum in the crankcase to 0-30 mbar.
exhaust system
The N62 engines feature a new exhaust system that optimizes gas exchange, acoustics and catalyst heating rate.
Exhaust system for the H62 engine: 1 - Exhaust manifold with built-in catalyst; 2 - Broadband lambda probes; 3 - Control probes (jump-like graphic characteristic); 4 - Exhaust pipe with front muffler; 5 - Intermediate muffler; 6 - Silencer damper; 7 - Rear muffler;
Exhaust manifold with catalytic converter
For each row of cylinders, one knee of the four-in-two-two-in-one design is provided. Together with the catalyst housing, the exhaust manifold forms a single unit.
Primary and main ceramic catalysts are located one behind the other in the catalyst housing.
The mounts for the broadband lambda probes (Bosch LSU 4.2) and control probes are located before and behind the catalytic converter in the front pipe or catalytic outlet funnel.
Muffler
There is one 1.8L front absorption muffler for each cylinder bank.
The two front mufflers are followed by one intermediate absorption muffler with a volume of 5.8 liters.
Rear reflection silencers have a volume of 12.6 and 16.6 liters.
muffler damper
The rear muffler is equipped with a damper to minimize noise. When the gear is engaged and the speed is over 1500 rpm, the muffler damper opens. This gives the rear muffler an extra volume of 14 liters.
The DME applies vacuum to the damper diaphragm via the solenoid valve.
Depending on the pressure, the diaphragm mechanism opens or closes the damper. The damper closes under the action of vacuum, and opens when air is supplied to the membrane mechanism.
This control is carried out using a solenoid valve, which is switched by the DME system.
Secondary air supply system
Due to the supply of additional (additional) air at the heating stage, afterburning of unburned residues occurs, which leads to a decrease in unburned hydrocarbons HC and carbon monoxide CO in the exhaust gas.
The energy released at the same time heats the catalyst faster in the warm-up stage and increases its level of neutralization.
Auxiliary and attachment equipment and belt drive
Belt drive
Belt drive engine N62
1 - Air conditioning compressor; 2 - 4-wedge corrugated belt; 3 - Crankshaft pulley; 4 - Coolant pump; 5 - Tensioner assembly of the main drive; 6 - Generator; 7 - Bypass roller; 8 - Power steering pump; 9 - 6-wedge corrugated belt; 10 - Air conditioner drive tensioner assembly;
The belt drive does not require maintenance.
Generator
Due to the high power of the generator (current 180 A) and the resulting heating, the generator is cooled by the engine cooling system. This method provides constant and uniform cooling.
The brushless alternator is supplied by Bosch. It is located in an aluminum housing flanged to the cylinder block. The outer walls of the generator are washed by the engine coolant.
As for the principle of operation and design, the generator is similar to that used with the M62 engine, only it has been slightly modified.
New is the BSD (Serial Binary Data Interface) interface to the DME control unit.
BMW N62 engine generator: 1 - Waterproof case; 2 - Rotor; 3 - Stator; 4 - Sealant;
Generator adjustment
Via BSD (Serial Binary Code Data Interface), the alternator can actively communicate with the engine control unit.
The generator tells the DME its data, such as type and manufacturer. This is necessary so that the engine management system can coordinate its calculations and set parameters with the type of generator that is installed.
DME takes on the following functions:
- turning the generator on/off based on the values stored in the DME
- calculation of the voltage setpoint to be set via the voltage regulator
- control of the generator's response to load surges (Load Response)
- diagnostics of the data transmission line between the generator and the engine management system
- storing generator trouble codes
- inclusion of a control lamp of a charge of the accumulator in a combination of devices
The DME can detect the following faults:
mechanical problems, such as blocking or failure of the belt drive
electrical faults, such as drive diode faulty or overvoltage or undervoltage caused by a faulty regulator
broken wire between DME and alternator
A winding break or short circuit is not recognized.
The performance of the generator's basic functions is guaranteed even if the BSD interface fails.
The DME can influence the alternator voltage via the BSD interface. Therefore, the charge voltage at the battery terminals can be up to 15.5 V, depending on the battery temperature.
If the battery charge voltage is measured up to 15.5 V at the service station, this does not mean that the regulator is faulty.
A high charge voltage indicates a low battery temperature.
Compressor
The compressor is a 7-cylinder swash plate compressor.
Compressor displacement can be reduced to 3% or less. This stops the supply of refrigerant to the air conditioning system. Inside the compressor, the refrigerant continues to circulate, providing reliable lubrication.
The compressor power is controlled by the A/C ECU using an external control valve.
The compressor is driven by a 4-ribbed ribbed belt.
N62 engine compressor: 1 - Control valve;
Starter
The starter is located on the left side of the engine under the output manifold. This is a compact intermediate starter with a power of 1.8 kW.
The location of the starter in the N62 engine: 1 - Starter with a thermal protective lining;
Power steering pump
The power steering pump is a tandem radial piston pump and is driven via a 6-ribbed serrated belt. Vehicles without Dynamic-Drive are fitted with a vane supercharger.
Cylinder heads
Both cylinder heads of the N62 engine are equipped with Valvetronic continuously variable valve actuators for valve actuation.
Additional air ducts are integrated into the cylinder heads for post-treatment of the exhaust gases.
The cylinder heads are cooled according to the principle of horizontal flow.
One support bridge supports the Valvetronic camshaft and eccentric shaft.
The cylinder heads are made of aluminium.
The cylinder head for the N62B48, due to the higher load, is made of aluminum-silicon alloy, and the combustion chamber diameter has been adapted to the larger cylinder diameter of the B48 version.
Engines N62B36 and N36B44 have different cylinder heads. They differ in the diameter of the combustion chamber and the diameter of the intake valves.
Cylinder heads in N62: 1 - Cylinder head row 1-4; 2 - Cylinder head row 5-8; 3 - The upper guide bar of the drive chain with an oil nozzle; 4 - Hole for the intake solenoid valve VANOS; 5 - Hole for the exhaust solenoid valve VANOS; 6 - Chain tensioner bracket; 7 - Hole for the intake solenoid valve VANOS; 8 - Hole for the exhaust solenoid valve VANOS; 9 - Oil pressure switch; 10 - Chain tensioner bracket; 11 - The upper guide bar of the drive chain with an oil nozzle;
Cylinder head gasket
The cylinder head gasket is a multilayer steel rubberized seal.
The sealing gaskets for the cylinder heads of the N62B36 and N52B44 engines differ in the diameter of the holes. Gaskets can be distinguished when they are installed. To do this, the N62V44 engine gasket has a 6 mm hole near the edge on the exhaust side, on the N62B48 the same two holes are located on the left next to the engine number.
cylinder head bolts
The cylinder head bolts of the N62 engine are all the same: extended bolts M10x160. In case of repair, they must always be replaced. The lower part of the timing block is attached to the cylinder head with M8x45 bolts.
Cylinder head covers
Cylinder head cover N62: 1-4 - Holes for rod ignition coils; 5 - Pressure control valve; 6 - Hole for the Valvetronic electric motor; 7 - Hole for the Valvetronic sensor connector; 8 - Camshaft position sensor;
Cylinder head covers are made of plastic. Guide sleeves for rod ignition coils (pos. 1-4) pass through the cover and are inserted into the cylinder head.
Plastic guide bushings for rod ignition coils that pass through the cylinder head cover to the spark plugs:
1-2 - Welded seals;
Plastic bushings have welded seals. If the seals are hardened or damaged, the entire sleeve must be replaced.
Valve drive
The valve drive of each of the two rows of cylinders is extended by components of the Valvetronic system.
Camshafts
The camshafts are cast from "bleached" cast iron. To reduce weight, they are made hollow. The camshafts are equipped with balancing masses to compensate for imbalances in the valve train.
1 - Wheels of camshaft position sensors; 2 - Thrust bearing section with lubrication channels for VANOS system components;
Dual VANOS (Variable Valve Timing)
The intake and exhaust camshafts of the N62 engine are equipped with new VANOS continuously variable vane units.
The maximum adjustment of the camshafts is 60 crankshaft degrees in 300ms.
The VANOS actuators are marked Ein/Aus (intake/exhaust) so that they are not confused during installation.
VANOS actuators
VANOS nodes for N62: 1 - VANOS node of the exhaust side; 2 - VANOS mounting bolt; 3 - Flat spring; 4 - VANOS assembly of the intake side; 5 — an asterisk of a gear chain;
The exhaust camshaft VANOS assembly for cylinders 1-4 is provided with a vacuum pump drive bracket.
VANOS solenoid valves
The solenoid valves of the VANOS system have the same design as those. Only the N62 engine has an O-ring.
How VANOS works
Adjustment process
Using the example of the VANOS assembly of the exhaust camshaft, the following graphic shows the adjustment process with the direction of the oil pressure. The direction of oil pressure is shown by red arrows. The drain (the area where there is no pressure) is indicated by a dotted blue arrow.
1 - View of the VANOS node from above; 2 - Side view of the VANOS node; 3 - Hole of the hydraulic system in the camshaft, pressure channel B; 4 - E / magnetic valve; 5 - Oil pump engine; 6 - Engine oil from the oil pump; 7 - Engine oil from the oil pump; 8 - Pressure channel A; 9 - Pressure channel B; 10 - Drain into the tank in the cylinder head;
The oil drains through the solenoid valve into the reservoir. The reservoir refers to the lubrication channel located in the cylinder head.
When adjusted in the opposite direction, the solenoid valve switches and other holes and channels in the camshaft and in the VANOS assembly open. In the following figure, the red arrow shows the direction of pressure. The oil drain is indicated by a dotted blue arrow.
Scheme for adjusting the VANOS of the exhaust side in the opposite direction: 1 - View of the VANOS unit from above; 2 - Side view of the VANOS node; 3 - Hole of the hydraulic system in the camshaft; 4 - E / magnetic valve; 5 - Oil pump engine; 6 - Draining engine oil into the cylinder head; 7 - Oil pressure from the oil pump;
If we consider the adjustment process only within the adjustment node, then it looks like this:
1 - Housing with a ring gear; 2 - Front panel; 3 - Torsion spring; 4 - Spring retainer; 5 - Latch cover; 6 - Retainer; 7 - Rotor; 8 - Rear panel; 9 - Blade; 10 - Spring; 11 - Pressure channel A; 12 - Pressure channel B;
The rotor (7) is bolted to the camshaft. The drive chain connects the crankshaft to the housing (1) of the VANOS assembly. The rotor (7) has springs (10) that press the blades (9) against the body. The rotor (7) has a recess into which, in the absence of pressure, the retainer (6) enters. When the solenoid valve supplies pressurized oil to the VANOS assembly, the latch (6) is released and the VANOS assembly is unlocked for adjustment. The oil pressure is transferred to the vane (9) in channel A (11) and thereby changes the position of the rotor (7). Since the rotor is connected to the camshaft, the valve timing changes.
If the VANOS solenoid valve is switched, the rotor (7) returns to its original position under the influence of oil pressure in the pressure port B (12). The action of the torsion spring (3) is directed against the moment of the camshaft.
To ensure reliable lubrication of the VANOS assembly, each camshaft has two O-rings at the end. It is necessary to pay attention to their impeccable position.
Valve timing diagram
The processes for adjusting the position of the intake and exhaust camshafts described above make it possible to draw up the following valve timing diagram:
New tools have been developed for removal / installation work on the valve actuator and for adjusting the valve timing of the N62 engine.
Valvetronic
Description of operation
Valvetronic combines the VANOS system and valve lift control. In this combination, the system controls both the beginning of the opening and closing of the intake valves, and the course of their opening.
The amount of air intake is controlled at open throttle by changing the stroke of the valves.
This allows you to set the optimal filling of the cylinders and leads to a reduction in fuel consumption.
Valvetronic is based on the system already known from the N42 engine, which has been adapted to the geometry of the N62 engine.
On the N62 engine, each cylinder head has one Valvetronic unit.
The Valvetronic assembly consists of a support bridge with an eccentric shaft, intermediate levers with retaining springs, tappets and an intake camshaft.
In addition, the Valvetronic system includes the following components:
- one Valvetronic electric motor for each cylinder head;
- Valvetronic control unit;
- one eccentric shaft sensor for each cylinder head;
Cylinder head row 1-4 in the N62 unit: 1 - Eccentric shaft; 2 - Support for the Valvetronic electric motor; 3 - Support jumper; 4 - Lubrication system of the valve drive; 5 - Upper guide bar of the drive chain; 6 - Oil pressure switch; 7 - Chain tensioner bracket; 8 - Exhaust camshaft; 9 - Socket for spark plugs; 10 + 11 - Wheel position sensors camshafts;
Valve Stroke Control System Components
Eccentric shaft adjustment motor
The valve stroke is controlled by two electric motors, which are activated by a separate control unit on commands from the DME system.
They rotate eccentric shafts through a worm gear, one per cylinder head. The guide for them is the reference jumper (Cam-Carrier).
Both Valvetronic electric motors are located with the power take-off side inward.
1 - Cylinder head cover, row 1-4; 2 - Valvetronic electric motor for adjusting the eccentric shaft;
Eccentric shaft sensor
Eccentric shaft sensors are installed in both cylinder heads above the magnetic wheels of the eccentric shafts. They inform the Valvetronic control unit of the exact position of the eccentric shafts.
Magnetic wheel (11) on eccentric shaft (5)
The wheels (11) of the eccentric shafts (5) contain powerful magnets. They allow the exact position of the eccentric shafts (5) to be determined using special sensors. The magnetic wheels are fixed to the eccentric shafts with non-ferromagnetic stainless steel bolts. Under no circumstances should ferromagnetic bolts be used for this purpose, otherwise the eccentric shaft sensors will give incorrect values.
The support web (Cam-Carrier) serves as a guide for the intake camshaft and eccentric shaft. In addition, it serves as a support for the valve stroke adjustment motor. The support bridge is matched to the cylinder head and cannot be replaced separately.
On the N62 engine, the roller tappets are made of sheet metal.
The stroke of the intake valves can be adjusted from 0.3 mm to 9.85 mm.
The Valvetronic mechanism works on the same principle as the N42 engine.
At the factory, the cylinder heads are assembled with high precision, which guarantees a strictly uniform air dosage.
The intake valve drive parts are carefully matched to each other.
Therefore, the bearing web and the lower bearings of the eccentric shaft and the intake camshaft are machined to a close tolerance when they are already installed in the cylinder head.
If the support web or lower supports are damaged, they are replaced only together with the cylinder head.
Valvetronic adjustment diagram
The graph shows the possibilities of adjusting VANOS and valve travel.
A feature of Valvetronic is that by changing the closing time and stroke of the valves, the intake air mass can be freely set.
chain drive
Chain drive of the N62 engine: 1 - Wheels of the camshaft position sensors, a number of cylinders 1-4; 2 - Tensioner bar, a number of cylinders 5-8; 3 - Chain tensioner, a number of cylinders 5-8; 4 - Wheel position sensors camshafts, a number of cylinders 5-8; 5 - The upper guide bar of the drive chain with a built-in oil nozzle; 6 - Plank of the chain damper; 7 - Oil pump drive sprocket; 8 - Lower cover of the drive chain; 9 — Strip tensioner, a number of cylinders 1-4; 10 - Solenoid valve, VANOS intake side; 11 - Solenoid valve, VANOS exhaust side; 12 - Top cover of the drive chain; 13 - Chain tensioner, a number of cylinders 1-4; 14 - VANOS of the release side; 15 - The upper guide bar of the drive chain with a built-in oil nozzle; 16 - VANOS intake side;
The camshafts of both rows of cylinders are driven by a toothed chain.
The oil pump is driven by a separate roller chain.
tooth chain
Timing chain BMW N62: 1 - Teeth
The camshafts are driven from the crankshaft by new, maintenance-free toothed chains. There are corresponding sprockets on the crankshaft and on the VANOS units.
The use of new toothed chains improves the rotation parameters of the drive chain on the sprockets and thus reduces the noise level.
crankshaft sprocket
1 - Toothed rim for the roller chain of the oil pump drive; 2 - Toothed rim for the gear chain of the camshaft drive; 3 - Crankshaft sprocket;
The crankshaft sprocket (3) has three gears: two gears (2) for the camshaft drive chain and one gear (1) for the oil pump roller chain.
This sprocket will also be installed on the 12-cylinder version of the engine in the future. When mounting, pay attention to the installation direction and the corresponding markings on the front side (V8 Front/V12 Front).
On the V-12 engine, the sprocket is installed on the opposite side: the gear ring of the oil pump back.
Cooling system
Coolant circuit
N62 engine coolant circuit: 1 - Cylinder head, row 5-8; 2 - Heating supply pipeline (right and left sections of the heat exchanger); 3 - Heating valves with electric water pump; 4 - Sealing gasket of the cylinder head; 5 - Heating supply pipeline; 6 - Ventilation pipeline of the cylinder head; 7 - Holes of the engine crankcase ventilation system; 8 - Oil pipelines of the gearbox; 9 - Liquid-oil heat exchanger automatic transmission; 10 - Thermostat of the gearbox heat exchanger; 11 - Generator housing; 12 - Radiator; 13 - Section of the low temperature of the radiator; 14 - Thermal sensor; 15 - Coolant pump; 16 - Removal of fluid from the radiator; 17 - Ventilation pipeline of the radiator; 18 - Expansion tank; 19 - Thermostat; 20 - Cylinder head, row 1-4; 21 - Heating the car; 22 - Section of the high temperature of the radiator;
An optimal cooling system solution was found, thanks to which the engine warms up in the shortest possible time during a cold start and at the same time cools well and evenly during operation.
The coolant washes the cylinder heads in the transverse direction (previously - in the longitudinal direction). This ensures a more even distribution of thermal energy over all cylinders.
The ventilation of the cooling system has been upgraded. It is carried out through the ventilation ducts in the cylinder heads and in the radiator (see general view of the cooling circuit).
The air from the cooling system is collected in the expansion tank.
Thanks to the use of ventilation channels, the system can not be pumped when replacing the coolant.
Coolant circulation in the N62 cylinder block: 1 - Fluid supply from the pump through the supply pipe to the rear end of the engine; 2 - Coolant from the cylinder walls to the thermostat; 3 - Connection pipe to the coolant pump / thermostat;
The coolant supplied by the pump enters through the supply pipeline (1), located in the space between the rows of cylinders, to the rear end of the cylinder block. This space is provided with a cast aluminum cover.
From there, the coolant flows to the outer walls of the cylinders, then to the cylinder heads (blue arrows).
From the cylinder head, fluid flows into the space between the rows of cylinders (red arrows) and through the pipe (3) to the thermostat.
If the fluid is still cold, it flows from the thermostat directly through the pump back into the cylinder block (small closed loop).
If the engine has warmed up to operating temperature (85 ° C -110 ° C), the thermostat closes the small coolant circuit and opens the large circuit with the radiator involved.
coolant pump
Coolant pump for the N62 engine: 1 - Programmable thermostat (fluid outlet from the radiator); 2 - Connector of the heating element of the programmable thermostat; 3 - Thermostat mixing chamber (in the coolant pump); 4 - Temperature sensor (at the outlet of the engine); 5 - Fluid supply to the radiator; 6 - Return pipeline of the gearbox heat exchanger; 7 - Leakage chamber (evaporation chamber); 8 - Supply pipeline to the generator; 9 - Coolant pump; 10 - Fitting, expansion tank;
The coolant pump is integrated with the thermostat housing and attached to the bottom cover of the timing chain.
Programmable thermostat
A programmable thermostat allows you to accurately control the degree of engine cooling depending on its operating modes. Thanks to this, fuel consumption is reduced by 1-2%.
Cooling module
Cooling module in N62: 1 - coolant radiator; 2 - Expansion tank; 3 - Coolant pump; 4 - Branch pipe of the air-oil heat exchanger of the engine; 5 - Liquid-oil heat exchanger gearbox;
The cooling module contains the following main components of the cooling system:
- coolant radiator;
- air conditioner condenser;
- liquid-oil heat exchanger gearbox with adjustment unit;
- fluid cooler for hydraulic systems;
- engine oil cooler;
- blowing electric fan;
- fan casing with viscous coupling;
All pipelines are connected by already known quick couplings.
coolant radiator
The radiator is made of aluminium. The baffle divides it into two sections connected in series: a high temperature section and a low temperature section.
The coolant first enters the high temperature section where it is cooled and then returned to the engine.
Part of the coolant after the high temperature section enters through the hole in the radiator baffle into the low temperature section and is cooled even more there.
From the low temperature section, the coolant enters the liquid-oil heat exchanger (if its thermostat is open).
Coolant expansion tank
The coolant expansion tank is removed from the cooling module and placed in the engine compartment next to the right wheel arch.
Liquid-oil heat exchanger gearbox
The gearbox oil-to-liquid heat exchanger on the one hand monitors the rapid heating of the oil in the gearbox, after which it ensures sufficient cooling of the gearbox oil.
When the engine is cold, the thermostat (10) turns on the oil-to-liquid gearbox heat exchanger in a short closed engine circuit. Thanks to this, the oil in the gearbox heats up in the shortest possible time.
The thermostat switches the transmission oil-to-liquid heat exchanger into the coolant cooler low temperature circuit when the temperature at its drain reaches 82°C. This cools the oil in the gearbox.
electric fan
The electric fan is built into the cooling module and creates pressure towards the radiator.
DME smoothly regulates the frequency of its rotation.
Viscous fan
The viscous fan is driven by a coolant pump. Compared to the E38M62 engine, the clutch and fan impeller have been optimized in terms of noise and performance.
The viscous fan is activated as the last cooling stage from an air temperature of 92 °C.
Cylinder block
oil sump
1 - The upper part of the oil sump; 2 - Oil pump; 3 - Oil condition sensor; 4 - The lower part of the oil sump; 5 - Filter element; 6 - Oil drain plug;
The oil sump consists of two parts.
The upper part of the oil sump is die-cast aluminium. Its joint with the crankcase is sealed with a rubberized sheet steel gasket.
Attached to the upper part of the oil sump is its lower part, which is made of a double metal sheet. Its joint with the upper part is sealed with a rubberized sheet steel gasket.
The upper part of the oil sump has a round hole for the oil filter element.
An o-ring is used to seal its connection to the oil pump.
crankcase
1 - The space between the rows of cylinders (coolant collection area);
The single-piece open deck crankcase is made entirely of aluminosilicate. Cylinder liners are hardened using a special technology.
Due to the different cylinder diameters (∅ 84 mm/92 mm/93 mm), the part numbers differ for the 3.5, 4.4 and 4.8 l engine versions.
Crankshaft
N62 engine crankshaft: 1 - crankshaft sprocket; 2-4 - Hollow sections of the crankshaft;
The crankshaft is made of induction hardened gray cast iron. To reduce weight in the area of bearings 2, 3, 4, the crankshaft is made hollow.
It has five pillars. The fifth support is also a thrust bearing.
A bearing consisting of a pair of half rings is used as a thrust bearing on the crankshaft side of the gearbox.
The width of the crankshaft has been adapted to the redesigned connecting rod and has been reduced from 42mm (N62B44) to 36mm (N62B48). To increase the displacement, the travel of the crankshaft journals increased from 82.7 mm to 88.3 mm.
Piston
The piston is cast, weight-optimized, with a cut-out in the skirt to the area of the piston rings and with “pockets” in the piston bottom.
The pistons are made of high heat resistant aluminum alloy and have three piston rings:
- Piston ring groove = flat ring
- Piston ring groove = scraper conical seat
- Piston ring groove = three-piece oil scraper ring
connecting rod
Forged steel connecting rod is made with a break.
The oblique (at an angle of 30 degrees) joint with the connecting rod rod made it possible to make the crank chamber very compact.
The pistons are cooled by oil jets in the crankcase on the outlet side of the piston head.
The pistons of the B36 and B44 engines differ in manufacturer and diameter.
In the case of processing cylinder mirrors, pistons of two repair sizes are available.
The connecting rods on the N62B44 are asymmetric, mounted on the N62B48 are symmetrical. The symmetrical arrangement of the cranks allowed for a more even distribution of force, and consequently it became possible to reduce the crank width from 21mm (N62B44) to 18mm (N62B48).
Flywheel
Flywheel - sheet typesetting. In this case, the gear rim and the incremental wheel (for determining the engine speed and crankshaft position) are riveted directly to the driven disk.
The flywheel diameter is 320 mm.
Vibration damper
The torsional vibration damper has an axially non-rigid design.
Engine Mount
The BMW H62 motor is suspended on two hydraulic mounting pads, which are located on the front axle beam. The design and principle of operation correspond to the M62 engine installed on.
Lubrication system
Oil circuit
Block crankcase N62 with oil nozzles: 1 - Oil nozzle of the chain drive for a number of cylinders 5-8; 2 - Oil nozzles for cooling the piston bottoms;
The filtered engine oil is supplied by an oil pump to lubrication and cooling points in the cylinder block and cylinder head.
In the crankcase and in the cylinder head, oil is supplied to the following parts.
crankcase:
- crankshaft bearings
- oil nozzles for cooling the piston crowns
- chain drive oil nozzle for cylinder bank 5-8
- chain tensioner strap for cylinder bank 1-4
Cylinder head:
- chain tensioner
- chain guide rail on cylinder head
- hydraulic pushers (elements of the compensation system
valve clearance) - VANOS power supply
- camshaft bearings
- valve train oil injectors
The N62B48 used shorter fuel injectors. They have been adapted to the longer stroke and should not be confused with the N62B44 injectors.
Oil Check Valves
Oil check valves in cylinder head N62:1 - Oil check valve for intake side VANOS unit; 2 - Oil check valve of the VANOS assembly on the exhaust side; 3 - Oil check valve for lubrication of the cylinder head;
Three oil check valves are screwed into each cylinder head from the outside. They prevent engine oil from draining from the cylinder head and VANOS units.
Due to the fact that the check valves are accessible from the outside, when replacing them, it is not necessary to remove the cylinder head.
All oil check valves are of the same design, so they cannot be confused.
Oil pressure switch
The oil pressure switch is located on the side of the cylinder head (banks 1-4).
Oil pump
Engine oil pump N62: 1 - Drive shaft; 2 - Threaded fastening; 3 - Oil filter; 4 - overpressure valve; 5 - Control valve; 6 - Oil pressure from the pump to the engine; 7 - Oil pressure control pipeline from the engine to the control valve;
The oil pump is a two-stage one with two pairs of gears connected in parallel, which is mounted on the crankshaft bearing caps at an angle. Its drive is carried out from the crankshaft by a roller chain.
Oil filter
The oil filter is located under the engine near the oil pan.
The bracket for the oil filter element is built into the back cover of the oil pump.
The oil filter cover is screwed through the hole in the oil sump into the rear cover of the oil pump. An oil drain plug is built into the oil filter cap to empty the filter element before unscrewing the cap.
There is a safety valve at the base of the filter element. When the filter element is clogged, this valve directs the engine oil, bypassing the filter, to the engine lubrication points.
Oil cooling
An oil cooler is installed on cars with a version for hot countries. The oil cooler is located in front of the engine coolant heat exchanger above the condenser in the cooling module.
Engine oil flows from the pump through a channel in the crankcase to a pipe on the generator bracket. There is an oil thermostat on the alternator bracket. An element in the oil thermostat keeps the oil cooler open at all times at an oil temperature in the range of 100-130°C.
Part of the oil always (even when the thermostat is fully open) passes by and enters the engine uncooled. This measure ensures that oil is supplied even if the oil cooler fails.
On vehicles without oil cooling, another alternator bracket is installed without oil thermostat pipes.
The N62B48 is equipped with a modified oil sump. The bottom section of the oil pan has been lowered by 16mm, minimizing the power loss that occurs in the crankcase as a result of pumping. The oil sump for the B48 was made of cast aluminum, and the lower section of the oil pan was made of 2 mm thick sheet steel, as a result it is less susceptible to mechanical stress compared to the B44.
ME9.2 engine management system
The N62 - ME9.2 engine management system is based on the N42 engine management system, but its functions have been expanded.
The DME (Digital Engine Electronics) control unit is located together with the Valvetronic control unit in the electronics box.
The DME controls the electronics box cooling fan.
The ECU connector has a modular design and consists of 5 modules with 134 pins.
All variants of the N62 engine use the same ME 9.2 block, which is programmed for use with a specific variant.
The ME 9.2 control unit is combined with BMW's own Valvetronic control unit. Both units take over the control functions of the N62 engine.
In this case, the task of the Valvetronic control unit is to control the stroke of the intake valves.
Description of operation
There is no direct connection to the OBD diagnostic plug. The DME is connected via the PT-CAN bus to the ZGM central gateway. The OBD plug is connected to the ZGM.
The DME activates the fuel pump via the ZGM and ISIS (Intelligent Security System) and via the airbag ECU in the SBSR (B-pillar right satellite).
This makes it possible to switch off the fuel pump even more quickly in the event of an accident.
The A/C compressor relay is not activated. The clutchless A/C compressor is now activated by the A/C control unit.
The DME signals required to control the compressor are transmitted to the A/C control unit via the PT-CAN via the ZGM.
FGR (cruise control) is integrated into the DME.
With N62 engines, a total of four lambda probes are installed.
In front of both primary catalytic converters, there is one wide-band lambda probe each for adjusting the composition of the fuel-air mixture.
Behind the main catalyst for each bank of cylinders is one probe to monitor the performance of the catalyst.
With the help of such a monitoring system, in the event of an unacceptably high concentration of harmful substances in the exhaust gas, the MIL warning lamp (malfunction indicator) is activated, and a fault code is stored in the memory.
Adjusting the composition of the mixture with lambda probes
Broadband lambda probe
The N62 engine is equipped with a new broadband lambda probe (primary catalytic converter probe).
The built-in heating element quickly provides the required operating temperature of at least 750 °C.
Design and function
1 - Exhaust gases; 2 - Pumping cell; 3 - Platinum electrode of the reference cell; 4 - Electrodes of the heating element; 5 - Heating element; 6 - Reference air gap; 7 - Zirconium-ceramic layer; 8 - Measuring gap; 9 - reference cell; 10 - Platinum electrodes of the reference cell; 11 - Platinum electrodes of the pumping cell (measuring cell); 12 - Platinum electrodes of the pumping cell;
Thanks to the combination in the sensitive element of the reference cell (9) for λ=1 and the pumping cell (2), which transports oxygen ions, the broadband lambda probe is able to measure not only at λ=1, but also in the rich and lean mixture ranges (λ= 0.7λ=air).
The pumping (2) and supporting (9) cells are made of zirconium dioxide and covered with two porous platinum electrodes. They are located in such a way that between them there is a measuring gap (8) with a height of 10 - 50 μm. The intake port connects this measuring gap to the surrounding exhaust gases. The voltage on the pumping cell is regulated by the DME electronic circuit in such a way that the gas composition in the measuring gap constantly has λ=1.
With a lean exhaust gas composition, the pumping cell pumps oxygen from the measuring gap to the outside, while with an enriched exhaust gas composition, the direction of the flow is reversed, and oxygen enters the exhaust gas in the measuring gap. The pump current is proportional to the oxygen concentration or demand for it.
The current consumption of the transfer cell is converted by the DME into an exhaust gas composition signal.
To operate, the probe needs ambient air as a reference inside the probe. Atmospheric air enters through the connector and then through the cable into the interior of the probe. Therefore, the connector must be protected from contamination (with wax, preservatives, etc.).
Signals
The lambda probe heating system is powered from the on-board network (13 V). The system is turned on and off by a mass signal from the control unit. Cyclicity is set through the characteristics field.
The lambda probe signal at a lambda value of 1 has a voltage of 1.5 V. At an infinite lambda value (clean air), the voltage is about 4.3 V.
The lambda probe has an imaginary mass of 2.5 V.
The reference cell of the lambda probe in a static state has a voltage of approx. 450 mV.
Oil level/condition
General provisions
Oil condition sensor in the removed lower part of the oil sump:
1 - Electronic sensor unit; 2 - Housing; 3 - The lower part of the oil sump;
To accurately measure the level, temperature and condition of the oil in the engine oil sump, an oil condition sensor is installed.
Measuring the oil level prevents it from falling and thus damaging the engine.
Tracking the condition of the oil allows you to accurately determine when it needs to be replaced.
Principle of operation
1 - Housing; 2 - Outer metal tube; 3 - Inner metal tube; 4 - Engine oil; 5 - Oil level sensor; 6 - Oil condition sensor; 7 - Electronic sensor unit; 8 - Oil sump; 9 - Thermal sensor;
The sensor consists of two cylindrical capacitors placed one above the other. The lower, smaller condenser (6) monitors the oil condition.
The electrodes of the capacitor are metal tubes (2 + 3) inserted one into the other. Between the electrodes is a dielectric - motor oil (4).
The electrical properties of engine oil change as the additives are worn down and reduced.
These changes (in the dielectric) lead to a change in the capacitance of the capacitor (oil condition sensor).
The digital sensor signal is transmitted to the DME as information about the condition of the engine oil. This sensor value is used by the DME to calculate the next oil change date.
The engine oil level is measured at the top of the sensor (5). This part is located in the oil sump at the oil level. When the oil (dielectric) level drops, the capacitance of the capacitor changes accordingly. The sensor electronics convert the capacitance value into a digital signal that is sent to the DME system.
To measure the oil temperature, a platinum temperature sensor (9) is installed at the heel of the oil condition sensor.
Oil level, temperature and condition are measured continuously as long as there is voltage on pin 87.
Possible malfunctions/consequences
The electronic circuit of the oil condition sensor has a self-diagnostic function. In the event of a fault in the OEZS, the DME system receives a corresponding message.
Variable geometry intake system
The intake system is adjusted using the drive unit. The drive unit is a 12 V DC electric motor with a worm gear and a potentiometer to confirm the position of the intake system.
Possible malfunctions / consequences
If the drive unit fails, the system stops in the current position. The driver may notice this by a loss of power or a decrease in smoothness.
Valvetronic
Electrical equipment and operation of the valve actuator with smooth stroke adjustment
The electrical equipment of the valve actuator with smooth stroke adjustment consists of the following components:
- Valvetronic control unit
- DME control unit
- DME main relay
- Valvetronic unloader relay
- two electric motors for adjusting eccentric shafts
- two eccentric shaft position sensors
- two magnetic wheels on eccentric shafts
DME - DME System; K1 - Main relay of the DME system; K2 - Unloading relay; M1 - Electric motor for adjusting the eccentric shaft, a number of cylinders 1-4; M2 - Electric motor for adjusting the eccentric shaft, a number of cylinders 5-8; VSG - Valvetronic ECU; S1 - Eccentric shaft sensor, cylinder bank 1-4; S2 - Eccentric shaft sensor, cylinder bank 5-8;
Description of operation
When terminal 15 is switched on, the main relay of the DME system is switched on and, in addition to the DME, supplies voltage to the on-board network to the Valvetronic control unit.
In the ECU, the electronic circuit operates at a voltage of 5 V.
The electronic circuit performs a pre-start check. With a certain delay (100 ms), the electronic circuit turns on the unloading relay, thus providing a load circuit for the servomotors.
From now on, communication between the DME control unit and the Valvetronic control unit takes place via the LoCAN bus. The DME determines with which valve stroke (depending on the load set by the driver) the gas exchange process should proceed.
The Valvetronic control unit sends a command to the DME system, activating the servomotors with a 16 kHz signal until the actual value of the eccentric shaft position sensor corresponds to the specified value.
Via LoCAN, the Valvetronic control unit informs the DME control unit of the position of the eccentric shaft.
Idle adjustment
The crankshaft speed control and thus the idle speed control is carried out by the Valvetronic system.
By reducing the valve stroke at idle, the corresponding amount of air is supplied to the engine.
With the introduction of the Valvetronic system, it was necessary to adapt the idle control system. During start-up and idling at engine temperatures ranging from -10 °C to 60 °C, the air flow is controlled by the throttle valve.
When the engine is warmed up to operating temperature, 60 seconds after starting, it switches to the mode without using the throttle. But at temperatures below -10 ° C, the start occurs at wide open throttle, as this has a positive effect on the start parameters.
If the idle speed control fails, first of all, you need to check the engine for leaks, since the resulting air leakage immediately affects the idle speed. This becomes noticeable, for example, even in the absence of an oil dipstick.
Engine power system
Mixture preparation system
The mixture preparation system of the E38M62 engine has been modified to adapt to the E65N62 engine, the following components have been modified.
The pressure in the supply system is 3.5 bar.
nozzles
The injectors were located closer to the intake valves. This increased the angle of the injected fuel jet.
Due to the greater atomization of the fuel, this leads to optimum mixture formation and thus to a reduction in fuel consumption and emissions.
The distribution lines have been optimized to achieve a more even distribution of fuel in order to achieve optimal engine smoothness at low speeds.
Fuel pressure control
The pressure regulator is built into the fuel filter. They are replaced as a set. The pressure regulator has only one return line: between it and the fuel tank.
The fuel pressure regulator is supplied with outside air pressure. In order to prevent leakage of fuel from leaking into the environment in the event of a leak in the pressure regulator, the intake system is connected to the pressure regulator by a hose. The end of the hose is located in the intake pipe behind the air mass meter.
Fuel pump (EKP)
The fuel pump is a two-stage pump with internal gears.
The first stage is the boost stage. It feeds the second pair of gears (fuel stage) with fuel that does not contain air bubbles. Both stages are driven by a common electric motor.
The fuel pump, like the E38 on the M62, is located in the mount in the fuel tank.
Electric fuel pump adjustment
The fuel supply is regulated depending on the needs of the engine.
Adjusting the electric fuel pump and cutting off the fuel supply in the event of a collision is the prerogative of ISIS (Integrated Security Intelligence).
Information about the required amount of fuel is transmitted from the DME via the PT-CAN bus and byteflight to the satellite in the right B-pillar (SBSR).
The ECR adjustment system is built into the SBSR (satellite in the right A-pillar).
The SBSR controls the electric fuel pump with a PWM signal depending on how much fuel the engine needs.
In SBSR, the current consumption of the electric fuel pump determines the current speed of the pump, from which the pumped amount of fuel is derived.
Then, after correction, depending on the pump speed (PWM control signal voltage), the required pump output is set according to the characteristic curve encoded in SBSR.
Possible malfunctions/consequences
When the fuel quantity request signals from the DME and the electric fuel pump speed signal to the SBSR disappear, the fuel pump operates with terminal 15 on at maximum capacity.
Even if control signals fail, this ensures uninterrupted fuel supply.
Fuel tank system
The fuel tank has a design similar to the E38 series. It is made of plastic and is mounted above the rear axle for safety reasons.
The tank capacity is 88 liters for positive ignition engines and 85 liters for diesel engines.
The reserve volume is for vehicles with an N62 engine = 10 liters, and with an N73 engine = 12 liters.
For safety and environmental reasons, the fuel tank system has a very complex structure. The tank consists of 2 halves, which is due to the place of its installation. One suction jet pump transfers fuel from the left side of the fuel tank to the right to the fuel pump.
Fuel Tank Leak Diagnostic Module (DMTL)
A Fuel Tank Leak Diagnostic Module (DMTL) is installed on US vehicles to detect leaks in the fuel tank system and vent.
It has a coasting function that is automatically started via the DME after terminal 15 is switched off if the evaluation criteria are met.
DMTL leaks as small as 0.5 mm are detected in the entire tank system. The presence of a leak is signaled by the MIL (malfunction indicator lamp).
Principle of operation
With the help of an electric air blower (vane) DMTL creates an excess pressure of 20-30 mbar in the fuel tank. The DME then measures the required pump current, which serves as an indirect value for the pressure in the tank.
Before each measurement, DMTL performs a comparative measurement. At the same time, for 10-15 s, pressure is built up relative to the reference leak of 0.5 mm and the pump current required for this is measured (20-30 mA).
If, during the subsequent pressurization, the pump current is lower than previously measured, this will serve as a signal that there is a leak in the power system.
If the current reference value is exceeded, the system is sealed.
Running Diagnostics
Diagnostics is performed in three stages. Its course is shown in the following diagrams.
1st stage- Purge activated carbon filter (AKF)
Running Diagnostics 1 - Purge Activated Carbon Filter:
2nd stage— A reference measurement is performed relative to the reference leak
Running diagnostics 2 - Reference measurement:
A - Throttle valve; B - To the engine; C - Outside air; 1 - TEV fuel tank ventilation valve; 2 - Activated carbon filter AKF; 3 - Fuel tank; 4 - DMTL fuel tank leak diagnostic module; 5 - Filter; 6 - Pump; 7 - Reference leak;
3rd stage- There is actually a leak test. Measurement continues:
60-220 seconds with sealed system
200-300 seconds at 0.5 mm leak
30-80 seconds for leaks >1 mm
During the measurement, the fuel tank vent valve is closed. The duration of the measurement depends on the fuel level in the tank.
Running Diagnosis 3 - Tank Measurement:
A - Throttle valve; B - To the engine; C - Outside air; 1 - TEV fuel tank ventilation valve; 2 - Activated carbon filter AKF; 3 - Fuel tank; 4 - DMTL fuel tank leak diagnostic module; 5 - Filter; 6 - Pump; 7 - Reference leak;
Conditions for running diagnostics
The main launch conditions are:
- engine off
- duration of last stop > 5 hours
- last engine run time > 20 minutes
BMW N62 engine - problems
The main and frequent malfunctions of this motor are the Valvetronic system, the VANOS variable valve timing system and valve seals.
But, with proper care and reasonable operation, this power unit will show itself very well. The following are some of the malfunctions that may occur during operation of the motor:
- excessive oil consumption: the reason is valve stem seals. This malfunction can occur with a run of about 100,000 km, and after 50-100,000 km oil scraper rings fail;
- revolutions float: the reason is the failure of the ignition coils, which should be checked or changed. Another possible cause is air leakage, a flow meter or Valvetronic;
- oil leakage: the reason is that the crankshaft oil seal or the sealing gasket of the generator housing, which must be replaced, is most likely leaking;
The BMW N62 engine has been replaced with a .
8-cylinder petrol engine N62TU
E60, E61, E63, E64, E65, E66, E70
Introduction
The N62TU engine is the result of the improvement of the N62 unit.
The N62TU 8-cylinder petrol engine has been redesigned. The engine compared to the N62 has become even more powerful and resourceful.
The N62TU has 2 displacement options: 4.0L and 4.8L. The current version of the digital engine management system is called DME 9.2.2.
Currently N62TU is used on E65, E66 (BMW 7 series).
Other start dates:
> E60, E61 (BMW 5 Series) and E63, E64 (BMW 6 Series): With 09/2005
> E63, E64 (BMW 6 Series): With 09/2005
new for N62TU is:
2-stage separate suction system with 2 DISA servomotors (each DISA servomotor has an output stage)
EURO 4 compliant, without secondary air system
Hot-wire air mass meter with digital signal
Electronic oil level control.
> Updated N62TU
Release start:
> E60, E61: With 03/2007
> E63, E64: With 09/2007
> E65, E66: With 09/2007
> E70 (BMW X5): With 09/2006
Innovations for N62TU:
New Digital Engine Electronics (DME 9.2.3)
New D-CAN diagnostic interface
D-CAN is a new diagnostic interface with a new communication protocol (instead of the old OBD interface). D-CAN transmits data between the vehicle and the BMW tester (D-CAN stands for "Diagnose-on-CAN"). D-CAN was first used on the E70.
> E65, E66 US version only
Measures to reduce CO 2 emissions (only European version):
The active air damper control system is used on the E60, E61 from 03/2007 (implementation on the E70 from 09/2007).
Engine Specifications:
The 8-cylinder petrol engine has the following specifications:
90A V8 engine
Valvetronic with its own control unit
2-Stage Variable Air Intake System (DISA)
Variable valve timing system (dual VANOS)
Built-in power module for DME and other components (except E70)
Story
| E65/735i | N62B36 | 200/272 | 360 | EURO 4 | DME 9.2* |
| E65/745i | N62B44 | 245/333 | 450 | EURO 4 | DME 9.2* |
| E60/545i | N62B44 | 245/333 | 450 | EURO 4 | DME 9.2.1* |
| E53/X5 4.4i | N62B44 | 235/320 | 440 | EURO 4 | DME 9.2.1* |
| E60/540i | N62B40TU | 225/306 | 390 | EURO 4 | DME 9.2.2* |
| E53/X5 4.8i | N62B48TU | 265/360 | 490 | EURO 3 | DME 9.2.1* |
| E60/550i | N62B48TU | 270/367 | 490 | EURO 4 | DME 9.2.2* |
| E70/X5 4.8i from 09/2006 |
N62B48TU | 261/355 | 475 | EURO 4 | DME 9.2.3* |
| E60/540i | N62B40TU | 225/306 | 390 | EURO 4 | DME 9.2.3* |
| E60/550i | N62B48TU | 270/367 | 490 | EURO 4 | DME 9.2.3 |
with separate Valvetronic control unit
Series information with implementation by 09/2007 with next update.
Brief description of the node
The V8 engine management system is described using the E65 as an example.
The N62TU engine control unit (DME) receives signals from the following sensors:
- 2 eccentric shaft sensors
The eccentric shaft sensor detects the position of the eccentric shaft in the presence of Valvetronic. The eccentric shaft sets the camshaft in such a position that in each mode of operation the optimal stroke of the intake valves is provided (the stroke of the intake valve varies in steps).
The position of the eccentric shaft is changed by the Valvetronic servomotor. The eccentric shaft sensor has 2 independent angle sensors. For safety reasons, 2 angle sensors with opposite characteristics are used. Both signals are digitized and transmitted to the Valvetronic ECU.
- 2 intake camshaft sensors and 2 exhaust camshaft sensors
The valve train is equipped with variable valve timing (Dual VANOS) for the intake camshaft and exhaust camshaft. Four camshaft position sensors detect changes in the position of the camshafts. To do this, there is a sensor wheel on the camshaft. The camshaft sensor is based on the Hall effect. The camshaft sensors are powered by the built-in power module.
- Accelerator pedal module
The accelerator pedal module determines the position of the accelerator pedal.
The DME control unit uses this and other factors to calculate the required Valvetronic or throttle position. The accelerator pedal module has 2 independent Hall sensors.
Each of them produces an electrical signal corresponding to the current position of the pedal. For security reasons, two sensors are used. They send out a signal proportional to the position of the accelerator pedal.
The second Hall sensor always produces a signal whose voltage is half that of the first. The voltage of both signals is constantly monitored by the DME.
The accelerator pedal module is supplied with a DC voltage of 5 volts from the DME. Both sensors have their own power supply circuit from the DME for safety reasons.
- Hot-wire air mass meter with intake air temperature sensor
Hot-wire air mass meter is used to determine the amount of intake air. Based on this data, the DME control unit calculates the degree of filling (basic value for the injection duration).
The temperature rise of the heated surface of the hot-wire sensor in the intake air flow is kept constant with respect to the intake air. The passing flow of intake air cools the heated surface. This leads to a change in resistance.
The amount of current required to maintain a constant temperature rise is a measure of the intake air volume. The new flow meter (HFM 6) has gone digital. The microcircuit present in the flow meter digitizes the sensor signal.
The flow meter sends a PWM signal to the DME.
The flowmeter is powered from the built-in power supply module.
Power supply via the front power distribution box in the electronically controlled power distribution box.
The hot-wire air mass meter also has an intake air temperature sensor built into it. The intake air temperature sensor is a negative temperature coefficient (NTC) resistor.
The intake air temperature is used by many DME functions, such as the following:
Determining the ignition timing
Correction of the knock control system
Idle adjustment
VANOS activation
Valvetronic activation
Electric fan activation
A faulty intake air temperature sensor causes a fault code to be stored in the DME memory. In this case, the equivalent value is used to control the motor.
- crankshaft position sensor
The crankshaft position sensor determines the position of the crankshaft using an incremental wheel bolted to the crankshaft. The crankshaft position sensor is required for multiport injection (individual injection into each cylinder, optimized with respect to ignition timing). The crankshaft sensor is based on the Hall effect.
The circumference of the incremental wheel has 60 identical teeth. The crankshaft sensor generates signal pulses. As the engine speed increases, the pulses become shorter and shorter. To synchronize injection and ignition, the exact position of the pistons must be known. Therefore, 2 teeth are missing on the incremental wheel.
The number of teeth between two gaps in the crown is constantly monitored. The camshaft sensor signals are constantly compared with the crankshaft sensor signal. All signals must be within the specified limits.
If the crankshaft sensor fails, the equivalent value is calculated from the signals from the camshaft sensors (when the engine is started and running).
Power is supplied to the crankshaft sensor from the built-in power module.
Power supply via the front power distribution box in the electronically controlled power distribution box.
- coolant temperature sensor
The coolant temperature sensor detects the temperature of the coolant in the engine cooling circuit.
The coolant temperature is the basis, for example, for the following calculations:
- Radiator outlet temperature sensor
The radiator outlet coolant temperature sensor detects the temperature of the coolant after the radiator.
The coolant temperature at the radiator outlet is required by the DME control unit, for example, to activate the electric fan.
- Intake manifold pressure sensor
If the car is equipped with an engine with Valvetronic system, then in the absence of throttling, there is no vacuum in the intake system. But for the operation of some functions and components, such as ventilation of the fuel tank or brake booster, vacuum is necessary. To do this, the electric throttle control is closed until the required vacuum is reached.
The intake manifold pressure sensor measures the vacuum in the intake system.
For engines with Valvetronic, for example, a vacuum of approx. 50 mbar. The value of the vacuum in the intake manifold serves in combination with other signals as an equivalent value for the load signal.
- 4 knock sensors
Four knock sensors register detonation during the combustion of the air-fuel mixture.
Piezoelectric knock sensors respond to vibrations in individual cylinders. The DME control unit evaluates the converted electrical signals separately for each of the cylinders. There is a special circuit in the DME for this purpose. Each of the knock sensors controls 2 cylinders. In turn, 2 knock sensors are combined into one unit.
- 4 lambda probes
On each side of the cylinders there is one lambda probe in front of the catalyst and one more behind it.
Lambda probes in front of the catalytic converter are working probes (regulating probe LSU 4.9).
Lambda probes downstream of the catalytic converter are already known probes with a relay characteristic (voltage jump at lambda = 1).
These lambda probes are control.
The lambda probes are heated by the DME control unit to quickly reach their operating temperature.
- Stoplight switch
The brake light switch has 2 switches: a brake light switch and a brake light test switch (redundant for safety purposes). Based on the signals, the DME control unit determines whether the brake pedal is depressed.
The Car Access System (CAS) supplies power to the brake light switch via the light module (LM) from terminal R.
Power is supplied directly from the CAS.
- clutch module
The clutch module has a clutch switch that detects when the DME control unit has pressed the clutch pedal (manual transmission).
The signal is important for internal torque control. So, for example, when the clutch pedal is pressed, the forced idle mode is not possible.
- Oil level sensor
The oil condition sensor has more functionality than the oil level temperature sensor.
The oil condition sensor determines the following parameters:
Engine oil temperature;
Oil level,
Oil quality.
From the sensor, the measurement results are sent to the DME.
For signaling, the serial data interface to the DME unit is used.
The oil condition sensor is powered by the built-in power module.
- Oil pressure indicator switch
The oil pressure indicator switch tells the DME control unit whether the engine oil pressure is sufficient.
The oil pressure indicator switch is connected to the built-in power module. Through the built-in power supply module, its signal is sent to the DME unit.
The oil pressure indicator switch is connected directly to the DME control unit.
The DME checks the signal from the oil pressure indicator switch for plausibility.
To do this, the signal from the oil pressure indicator switch is analyzed after the engine has been switched off.
If, after a certain time, the switch still registers oil pressure, although it should not, then a fault code is stored in the DME unit.
The following control units and other components are involved in the operation of the digital engine electronics (DME):
- DME control unit
There are 3 sensors on the board in the DME control unit:
The temperature sensor serves to monitor the temperature of the components in the DME control unit.
Ambient pressure is required to calculate the composition of the mixture. Ambient pressure decreases with increasing altitude.
The voltage sensor on the DME control unit board monitors the power supply via terminal 87.
The DME control unit is connected to the on-board network via 5 connectors.
The DME control unit is connected via the PT-CAN and the Safety and Gateway Module (SGM) to the rest of the bus system.
> E60, E61, E63, E64 from 09/2005
The gateway between the PT-CAN bus and the rest of the bus system is the body gateway module (KGM).
The gateway between the PT-CAN and the rest of the bus system is the electronic control unit JBE.
- ECU Valvetronic
The eight-cylinder petrol engine has its own Valvetronic control unit.
Communication between the DME and Valvetronic control units takes place via a separate Local-CAN bus (local two-wire CAN bus).
On a separate wire, the DME unit puts the Valvetronic control unit into an active state.
The DME control unit calculates all the values necessary to activate the Valvetronic system. The Valvetronic control unit evaluates the signals from both eccentric shaft sensors. To change the position of the eccentric shaft, the Valvetronic control unit controls the Valvetronic servomotor.
Power is supplied to the Valvetronic control unit via the Valvetronic relay, located in the built-in power module.
Power is supplied to the Valvetronic control unit via the front power box in the front junction box.
The Valvetronic control unit constantly checks whether the actual position of the eccentric shaft corresponds to the specified one. This allows you to recognize the tight movement of the mechanism. In the event of a malfunction, the valves open as far as possible. And then the air supply is regulated by a throttle valve.
- Built-in power module
> N62TU on E70
There is no built-in power module on the E70.
The eight-cylinder petrol engine has a built-in power module. The built-in power module contains various fuses and relays (this is not a control unit, but a distribution unit). The built-in power module serves as the central link between the vehicle cabling and the engine wiring harness.
The PT-CAN bus also passes through the built-in power supply module.
- CAS control unit
The electronic anti-theft system (EWS) is integrated into the CAS control unit, which serves as protection against thieves and car thieves.
The engine may only be started with the permission of the EWS.
In addition, the CAS control unit sends a signal to the DME to wake up (terminal 15 Wake-up) the PT-CAN bus.
The CAS control unit activates the starter (comfort start).
The DME unit turns on the starter.
- Generator
The alternator communicates with the DME control unit via a binary serial data interface. The alternator sends information to the DME control unit such as type and manufacturer. This allows the DME ECU to adjust the alternator according to the type of alternator installed.
- ECU DSC
The DSC control unit sends a speed signal to the DME control unit via a separate wire (duplication of the PT-CAN bus signal). This signal is required for many functions, such as maintaining the set speed or limiting the speed.
- instrument cluster
The outside temperature sensor sends a signal to the instrument cluster.
The instrument cluster sends this signal further down the bus to the DME.
The outside temperature is a value necessary for the operation of many functions in the engine control unit.
If the outside temperature sensor fails, a fault code is stored in the DME control unit. The DME calculates an equivalent value from the intake air temperature.
The instrument cluster includes the DME indicator and warning lamps, eg the exhaust gas warning lamp. The instrument cluster displays the available Check Control messages.
The tank filling level sensor is also connected to the instrument cluster. The instrument cluster sends the filling level sensor signal as a CAN message. The DME system uses the tank level CAN message to disable low misfire detection and also to enable DMTL (DMTL stands for "Fuel Tank Leak Diagnostic Module").
- Air conditioning compressor
The DME control unit is connected by a bus system to the integrated automatic heating and air conditioning system (IHKA). IHKA turns the A/C compressor on and off.
The signal for this is sent to the IHKA by the DME via the bus.
Active Steering, Active Cruise Control, Electronic Transmission Control
The DME control unit is connected via a bus system to the following control units (depending on vehicle equipment):
These connections are necessary for torque control.
The Digital Engine Electronics (DME) controls the following actuators:
- 2 Valvetronic servomotors - via Valvetronic control unit
The amount of air supplied to the engine in throttleless mode is not controlled by the throttle, but by changing the stroke of the valves.
Valvetronic is driven by an electric motor. The Valvetronic servomotor is mounted on the cylinder head. The Valvetronic servo motor rotates the eccentric shaft in the lubricated space of the cylinder head by means of a worm gear.
The eccentric shaft sensor signals the position of the eccentric shaft to the DME control unit via the Valvetronic control unit.
- 2 DISA servo motors with variable intake tract length
The N62TU engine has a two-stage split air intake system (DISA).
The DISA servomotor drives four sliding sleeves for each side of the cylinder.
Sliding sleeves lengthen or shorten the inlet.
This makes it possible to achieve a perceptible change in torque at low engine speeds without loss of engine power at high engine speeds.
- Electric throttle control
The DME control unit calculates the throttle position from the position of the accelerator pedal and from torque requests from other control units. The throttle valve position is controlled in the electric throttle valve controller by 2 potentiometers.
The electric throttle control is opened or closed by the DME control unit.
- 4 VANOS solenoid valves
The variable valve timing system of the intake valves is used to increase torque in the lower and middle ranges of the engine speed.
One VANOS solenoid valve controls the VANOS adjustment unit on the intake side and one on the exhaust side.
The VANOS solenoid valves are activated by the DME control unit.
- Fuel electric pump
The electric fuel pump is actuated as needed by a satellite in the right B-pillar.
The following control units are involved in regulating the operation of the fuel pump:
The DME control unit monitors the activation of the fuel pump relay. The fuel pump relay is only activated by the safety circuit when the engine is running and immediately after terminal 15 is turned on to build up pressure (fuel pump pre-mode).
- 8 nozzles
With multipoint injection, each injector is activated by the DME control unit via its own output stage.
In this case, the moment of injection into one or another cylinder is consistent with the operating mode (speed, load, engine temperature).
The injectors are powered by a built-in power supply module.
- Fuel tank vent valve
The tank vent valve is designed to regenerate the activated charcoal filter by supplying purge air. Scavenging air drawn in through an activated carbon filter is enriched with hydrocarbons and then fed into the engine.
The fuel tank vent valve is powered by the built-in power module.
The fuel tank vent valve is powered from the rear power distribution box.
- 8 ignition coils with unloader relay
The ignition coils are activated by the DME control unit. The unloader relay in the built-in power module supplies power to the ignition coils.
Without built-in power module; the unloading relay is installed separately.
- Programmable thermostat
The programmable thermostat opens and closes according to the characteristic field.
The programmable thermostat maintains a constant coolant temperature at the engine inlet within its adjustment range.
At low load, the programmable thermostat sets the coolant temperature to high (ECO mode).
At full load or high speeds, the coolant temperature is lowered to protect components.
The programmable thermostat is powered by the built-in power module.
The programmable thermostat is powered through the front power box in the front junction box.
- electric fan
The electric fan is activated by the DME control unit with a pulse-width modulated signal (analyzed by the fan electronics).
The DME control unit uses a pulse-width modulated signal (10-90%) to control the fan speed.
A duty cycle of less than 5% and more than 95% does not cause activation, but is used for fault detection.
The speed of rotation of the electric fan depends on the temperature of the coolant at the outlet of the radiator and the pressure in the air conditioner. With an increase in the speed of movement, the speed of rotation of the electric fan decreases.
- Electronics box fan
The control electronics compartment gets very hot.
Heating is caused both by the influence of high temperatures from the outside, and with the heating of the control units inside the compartment. The control units have a limited operating temperature range, so a fan is installed in the electronics box.
The operating temperature must not be exceeded. The lower the temperature, the longer the life of electronic components and parts.
- muffler damper
The E70 does not have a muffler flap.
A membrane mechanism is installed on the right exhaust pipe of the rear muffler. Through the position adjustment mechanism, it is connected to the muffler damper.
The membrane mechanism is connected by a vacuum hose to a solenoid valve.
The muffler damper reduces the noise level at idle and in the speed range of the crankshaft close to idle.
At low speed or the engine is off, the muffler flap is closed. When the speed increases, it opens.
The DME controls the muffler damper solenoid valve. When underpressure, the muffler damper opens. This happens at a certain load and speed.
When the engine is turned off, air is supplied to the membrane mechanism through the throttle. Therefore, the muffler damper does not close abruptly. The shutdown valve is controlled by the power supply module (PM).
System functions
The following system functions are described:
Power management.
Electronic anti-theft system
Comfortable start
Air supply: 2-stage intake system with a variable length of the intake tract "DISA"
Filling control
Variable stroke valve actuator "Valvetronic"
Variable valve timing "VANOS"
Fuel supply system
Ignition circuit monitoring
Generator activation
Lubrication system
Engine cooling
Knock control system
Fuel tank ventilation
Lambda value adjustment
Torque control
Analysis of the speed signal
Air conditioning compressor activation
Intelligent generator control
Active damper control
Power Management
The integrated power module supplies the supply voltage to the DME control unit.
Three relays in the built-in power supply distribute power from pin 87 to various nodes.
For memory functions, the DME control unit needs a permanent supply via terminal 30. The power supply from terminal 30 is also supplied by the integrated power supply module.
The DME control unit is connected to earth via several pins, which are interconnected in the control unit.
Power management includes the following features:
The battery voltage is constantly monitored by the DME control unit. When the battery voltage is less than 6 V or more than 24 V, a fault code is recorded.
Diagnostics is activated only 3 minutes after the engine is started. In this case, the influence of the starting process or starting aid on the battery voltage is not qualified as a malfunction.
> E60, E61, E63, E64
The Intelligent Battery Sensor (IBS) monitors the battery. The smart battery sensor is connected to a serial data bus (BSD).
> E70
The fuse holder provides power to the DME control unit via the front power distribution box in the electronic power distribution box (for terminals 30 and 87).
The Intelligent Battery Sensor (IBS) monitors the battery.
Electronic anti-theft system
The electronic anti-theft system serves as a security system and controls the start release.
The CAS control unit controls the electronic anti-theft system.
Each remote control has a transponder chip. There is a ring antenna around the ignition switch.
The transponder chip receives power from the CAS ECU via this winding (the battery in the remote control is not required).
Power and data transmission are carried out according to the principle of a transformer. To do this, the remote control sends identification data to the CAS control unit.
If the identification data is correct, the CAS ECU activates the starter using a relay located in the control unit.
At the same time, the CAS control unit sends a coded enable signal (variable code) to start the engine to the DME control unit. The DME control unit only allows starting when an enable signal is received from the CAS control unit.
These processes can lead to a slight start delay (up to half a second).
The following fault codes are stored in the DME control unit:
If a fault is detected, the engine start is blocked.
Comfortable start
With a comfort start, the starter automatically engages and remains engaged until the engine starts.
After pressing the START-STOP button, the CAS control unit first activates terminal 15. This switches on the unloading relay of the ignition coils.
When the START-STOP button is pressed, the CAS control unit checks whether the brake pedal is depressed and whether the selector lever is in position P or N.
The engine is started as follows:
> E65, E66 and also E70
The DME unit turns on the starter.
If the engine does not start, contacts 50L and 50E are switched off after 20 seconds at the latest. And then the engine start is interrupted.
Air supply: 2-stage intake system with a variable length of the intake tract "DISA"
Under the action of the intake strokes of the pistons, pressure waves form in the intake manifold.
These pressure waves propagate along the intake manifold. Pressure waves bounce off closed intake valves.
The length of the intake manifold, precisely coordinated with the valve timing, has the following effect:
just before the intake valve closes, the pressure ridge of the reflected air wave reaches the valve. This allows more air to enter. This additional amount of air increases the amount of air in the cylinder.
Thanks to the intake system with a variable length of the intake tract, the advantages of a short and long intake manifold are simultaneously used.
Before the deflecting branch pipe, the preliminary branch pipe is switched on accordingly. When the sliding sleeve is closed, the pre-pipe and the deflector work together as a long intake manifold.
The air column pulsating in it significantly increases the torque in the middle speed range.
To increase power in the upper speed range, the sliding sleeves open. The dynamics of the preliminary nozzles decreases in this case. The short intake pipes now in operation provide high power in the upper speed range.
The DME control unit changes the position of the sliding sleeves using two DISA servomotors (12 V) with an integrated gearbox. Each DISA servomotor has an output stage. The DME control unit remembers whether an upshift or a downshift has been performed.
When the engine speed drops below 4700 rpm, the DME control unit uses the DISA servo motors to close the sliding sleeves. Above 4800 rpm, the sliding sleeves open again (N62B40TU: 4800 and 4900 rpm). These switching speeds are shifted (hysteresis) to prevent frequent opening and closing.
When the system fails, the sliding sleeves remain in the appropriate position. For the driver, the failure of the system is manifested in a loss of power and a decrease in maximum speed.
After the engine is stopped (terminal 15 switched off), the sliding sleeves reach their stop.
This prevents the formation of deposits and blocking of sliding sleeves during long periods of movement at low speeds.
Filling control
The following input values serve the purpose of filling control by the DME:
From these 4 input values, the DME calculates the filling for all operating modes.
Variable stroke valve actuator "Valvetronic"
Valvetronic is designed to reduce fuel consumption.
The amount of air supplied to the engine, with active Valvetronic, is not set by the throttle control, but by changing the stroke of the intake valves.
The electrically driven eccentric shaft changes the action of the camshaft to the roller tappet lever by means of an intermediate lever. This results in a variable valve stroke.
The throttle valve controller, if fitted with Valvetronic, is activated for the following functions:
In all other operating modes, the throttle valve is opened just enough to create only a slight vacuum.
This vacuum is required, for example, to vent the fuel tank.
Based on the accelerator pedal position and other values, the DME control unit calculates the corresponding Valvetronic position.
The DME control unit controls the Valvetronic servomotor on the cylinder head via the Valvetronic unit. The Valvetronic servo motor rotates the eccentric shaft in the lubricated space of the cylinder head by means of a worm gear.
The eccentric shaft sensor determines the current position of the eccentric shaft. The eccentric shaft sensor has 2 independent angle sensors.
The Valvetronic control unit, using the Valvetronic servo motor, changes the current position until it reaches the set one.
For reliability, 2 angle sensors with opposite characteristics are used. The signals from both sensors are transmitted digitally by the DME control unit. Both angle sensors receive a supply voltage of 5 V from the DME control unit.
Both signals from the eccentric shaft sensor are constantly monitored by the DME control unit.
The plausibility of the signals is checked separately and together. Both signals should not differ from each other. In the event of a short circuit or a fault, the signals are out of the measuring range.
The DME control unit constantly checks whether the actual position of the eccentric shaft is correct. This allows you to recognize the tight movement of the mechanism.
In the event of a malfunction, the valves open as far as possible. The air supply is controlled by a throttle valve.
If the instantaneous position of the eccentric shaft cannot be recognized, the valves open to the maximum and are no longer controlled (controlled emergency operation).
In order to achieve the correct opening of the valves, all tolerances in the valve actuator must be compensated by means of a correction. In this correction process, the position of the eccentric shaft is changed from stop to stop.
The positions obtained in this way are stored in memory. At each operating moment, they serve as a reference position for calculating the instantaneous value of the valve travel.
The correction process starts automatically: at each restart, the position of the eccentric shaft is compared with the values stored in the memory. If, for example, a different position of the eccentric shaft is detected after repair work, a correction process is carried out. In addition, the correction can be called up using the BMW diagnostic system.
Variable valve timing "VANOS"
The variable valve timing system improves the torque in the low and middle speed ranges.
More valve overlap reduces the amount of exhaust gases at idle. Internal exhaust gas recirculation in the partial load range reduces the emission of nitrogen oxides.
In addition, the following is provided:
Each of the camshafts (inlet and outlet) has one adjustable VANOS adjustment unit (adjustment via oil pressure).
The VANOS solenoid valve is used to actuate the VANOS adjustment unit. Based on the speed and the load signal, the required position of the intake and exhaust camshafts is calculated (depending on the intake air temperature and engine temperature). The DME control unit respectively activates the VANOS control unit.
The position of the intake and exhaust camshafts varies within their maximum adjustment ranges.
When the correct camshaft position is reached, the VANOS solenoid valves keep the volumes of hydraulic fluid in the slave cylinders constant in both chambers. This keeps the camshafts in this position.
The variable valve timing system requires feedback on the current position of the camshafts to adjust the position. One position sensor on the intake and exhaust camshafts determines their position.
When the engine is started, the intake camshaft is in the end position (in the "spaet" position). The exhaust camshaft is spring loaded and held in the early position when the engine is started.
Fuel supply system
The BMW 7 Series has a demand-driven, consumption-based power system.
The DME calculates the required injection quantity from the various operating values.
This value is used to calculate the current fuel demand of the engine. The DME requests this value as a flow rate with the unit of measure "liter per hour".
DME sends a request along the following path: DME -> PT-CAN -> SGM -> byteflight-> SBSR (satellite in the right B-pillar) -> EKP (variable fuel pump).
The satellite in the right B-pillar converts the value of the requested amount of fuel into a given speed value for the fuel pump.
The pump speed is controlled by the duty cycle of the PWM signal. This square wave gives the effective fuel pump supply voltage: The longer the pause between the front lines of the square wave, the lower the fuel pump supply voltage. And, accordingly, the lower the performance of the fuel pump. The speed of the fuel pump is reported as an input signal to the satellite in the right B-pillar.
This provides the following advantages over the traditional fuel pump control circuit (via a relay):
In the event of an accident of sufficient severity, the fuel supply is interrupted. This prevents fuel from escaping and igniting (fuel cut-off in the event of an accident).
The fuel pump can be reactivated by switching the ignition off and on again.
If the request signal from the DME or the PWM signal from the SBSR disappears: the fuel pump is operating at maximum capacity. This guarantees sufficient fuel supply in all operating modes (emergency mode).
> E60, E61, E63, E64 and also E70
The DME turns on the fuel pump via the pump relay.
Injection
With multiport injection, each injector is activated by its own output stage.
Distributed injection has the following advantages:
By activating each individual injector with its own output stage, uniform fuel filling of all cylinders is achieved. This ensures equally good preparation of the working mixture.
Fuel filling time may vary and depends on load, engine speed and engine temperature.
Since the injection is carried out only once for each revolution of the camshaft, the dispersion of the injected fuel quantity is reduced due to the tolerances of the components.
The smoothness of idling is also improved, as the opening and closing times of the injectors are reduced.
In addition, fuel consumption is somewhat reduced.
While driving, when accelerating suddenly or releasing the accelerator pedal, the injection duration can be adjusted. If the nozzles are still open, you can adjust the mixture composition by increasing or decreasing the injection duration for all nozzles. In this case, the best parameters of engine response are achieved.
Ignition circuit monitoring
The secondary circuit of the ignition system is controlled by the current in the primary winding of the ignition coil. In the process of switching on, the current must change within a certain time within certain limits.
When diagnosing the ignition system, the following are checked:
The following faults are recognized by monitoring the ignition circuits:
Not recognized:
Generator Activation (Binary Serial Communication Interface)
For an alternator with a serial binary data interface (BSD), the DME control unit implements the following functions:
> from 03/2007 to E60, E61
> from 09/2007 to E63, E64, E70
The main function of the alternator is also maintained in the event of a communication failure between the alternator and the DME control unit.
The fault codes can be used to identify the following possible causes of the fault:
the generator is overloaded. For safety, the alternator voltage is reduced so that the alternator can cool down again (without turning on the charge indicator lamp).
the generator is mechanically blocked. Or: the belt drive is faulty.
the diode in the excitation winding circuit is faulty, an open in the excitation winding, increased voltage due to a malfunction of the regulator.
Faulty wire between DME control unit and alternator.
An open or short circuit in the generator windings was not recognized.
Lubrication system
The oil condition sensor informs the DME control unit of the level and quality of the engine oil. The temperature sensor in the oil condition sensor reports the engine oil temperature. The engine oil temperature, together with the coolant temperature, is used to calculate the engine temperature.
The oil pressure is reported by the oil pressure indicator switch.
The oil level is also measured for the electronic oil level control system. A second capacitor located at the top of the oil condition sensor measures the oil level. The condenser is at the same height as the oil level in the oil sump.
When the oil level drops, the capacitance of the capacitor changes. The processing electronics generates a digital signal based on this. The DME system calculates the engine oil level.
The DME control unit controls the signal and indicator lamp in the instrument cluster via the PT-CAN (red: low oil pressure; yellow: low oil level).
Electronic oil level control:
The oil dipstick now has a black handle. The engine oil level is measured by an oil condition sensor.
The measured value is displayed on the Central Information Display (CID).
The signal from the oil condition sensor is processed by the digital electronic engine management system. In addition to the oil level, the temperature sensor determines the temperature of the oil in the engine.
MOT by state:
For the condition-based service indicator (CBS), the quality of the engine oil is additionally measured.
The electrical properties of an oil change as it ages. A change in the electrical properties of the engine oil (dielectric) leads to a change in the capacitance of the oil condition sensor capacitor.
The electronic circuit converts the capacitance value into a digital signal.
The digital sensor signal is transmitted to the DME as a result of the oil quality assessment.
From this, DME calculates when the next oil change is due under Condition Based Maintenance (CBS).
Engine cooling
The programmable thermostat opens and closes according to the characteristic field. This adjustment can be divided into 3 operating ranges:
coolant only flows into the engine. The cooling circuit is closed.
all coolant flows through the radiator. In this case, the maximum possible cooling intensity is used.
part of the coolant flows through the radiator. The programmable thermostat maintains a constant temperature of the coolant at the engine outlet within the control range.
In this operating range, the coolant temperature can only be specifically influenced by a programmable thermostat. In this case, a higher coolant temperature can be set in the partial load range of the engine. A higher operating temperature in the partial load range ensures better combustion. This results in reduced fuel consumption and emissions.
In full load mode, high operating temperature brings disadvantages (decrease in ignition timing due to knocking).
Therefore, in full load mode, a programmable thermostat sets a lower coolant temperature.
Knock control system
The engine is equipped with an adaptive knock control system that takes into account each cylinder.
Four sensors register detonation during the combustion of the working mixture (cylinders 1 and 2, cylinders 3 and 4, cylinders 5 and 6, cylinders 7 and 8). The sensor signals are evaluated in the DME control unit.
Prolonged operation of the engine with detonation can cause severe damage.
Detonation contributes to:
The compression ratio can be too high also due to variations caused by deposits or manufacturing. In the absence of a knock control system, these negative influences must be taken into account. Cylinders must be designed in such a way that the detonation boundaries have a certain margin. At the same time, in the range of large loads, the impact on work efficiency is inevitable.
The knock control system prevents detonation. Only in the event of an actual risk of knocking is the ignition timing of the corresponding cylinder or cylinders (including the cylinder) changed as necessary.
In this case, the field of ignition characteristics can be calculated for values that are optimal in terms of fuel consumption (without taking into account the detonation limit). Safe distance from the border is no longer required.
The knock control system takes care of all knock-related adjustments to the ignition timing and enables flawless driving even with regular petrol (minimum ROZ 91). The knock control system provides:
The knock control system self-diagnosis includes the following checks:
If one of these checks detects a malfunction, the knock control system is disabled. The ignition timing control goes into the emergency program. At the same time, a fault code is stored in the fault memory. The emergency program ensures damage-free operation with a minimum of ROZ 91 petrol. The emergency program depends on the load, engine speed and temperature.
Fuel tank ventilation
The fuel tank vent valve controls the regeneration of the activated carbon filter by supplying purge air.
The purge air sucked in through the activated carbon filter is enriched with hydrocarbons (HC) depending on how full the filter is. The scavenging air is then fed into the engine for combustion.
The formation of hydrocarbons in the fuel tank depends on:
The fuel tank vent valve is closed when de-energized. This prevents fuel vapor from entering the intake manifold from the activated carbon filter when the engine is not running.
Lambda value adjustment
Optimum catalytic efficiency is only achieved when combustion is carried out with an ideal fuel-to-air ratio (For this, lambda probes are used before and after the catalytic converter.
Lambda probes before the catalytic converter have a constant characteristic (measurement of the oxygen content in the lean and rich mixture ranges).
These lambda probes have a different measuring principle compared to lambda probes with jump characteristic. Therefore, these lambda probes have 6 pins instead of 4.
Lambda probes upstream of the catalytic converter (control probes) are used to evaluate the exhaust gas composition.
Adjustment probes are screwed into the exhaust manifold.
Lambda probes measure the oxygen content in the exhaust gas. The resulting voltage values are transmitted to the DME control unit. The DME control unit adjusts the composition of the mixture through the duration of the injection.
Depending on the operating mode, adjustment is carried out towards more or less
Lambda probes downstream of the catalytic converter (control probes) serve to monitor the control probes. In addition, the operation of the catalyst is monitored.
A temperature of approx. 750 AA for lambda probes behind the catalyst). For this reason, all lambda probes are heated.
The lambda probe heating is activated by the DME control unit. When the engine is cold, the lambda probe heating remains switched off, as existing condensate can destroy the hot lambda probe due to thermal stresses.
Therefore, the lambda control becomes active only after the engine is started, when the catalytic converters have already warmed up. The lambda probe is first preheated with a low heating power in order to eliminate the load due to thermal stresses.
Torque control
The DME controls the requested torque.
The following systems request torque from the DME control unit:
Analysis of the speed signal
The road speed signal is required by the DME control unit for several functions:
When the maximum speed is reached, injection and ignition change. If necessary, the individual ignition and injection signals are suppressed. In this case, a "soft" speed control is performed.
When the air conditioner is on, in the event of acceleration at full load, the air conditioner compressor turns off.
The condition for this is: the driving speed is less than 13 km/h.
If the speed is 0 km/h, the idle speed is adjusted (depending on the activation of the air conditioning compressor, the position of the automatic transmission, the lighting).
At low speeds, the check for smooth running of the engine is disabled.
Air conditioning compressor activation
The signal to activate the air conditioning compressor is sent by the DME control unit.
The A/C compressor turns off under the following conditions:
The A/C compressor is activated by IHKA. The DME sends a signal over the bus.
Intelligent generator control
The intelligent alternator control regulates the charge state of the battery in a targeted manner.
The battery is charged primarily in the forced idle mode.
Depending on the state of charge, the battery is not charged during the acceleration phase.
Active damper control
The active air damper control regulates the air supply for cooling the engine and components, opening the air dampers only when necessary.
Service instructions
When servicing, follow the instructions below:
Coding/Programming: ---
US national version
Fuel Tank Leak Diagnostic Module
Checking the tightness of the power supply system is carried out regularly after turning off the engine. When in the inertial phase of the DME, the following processes occur:
initial situation
During normal engine operation, the diverter valve in the diagnostic module is in the "Regeneration" position. Fuel vapors are collected in the activated charcoal filter and, depending on the activation of the tank vent valve, are led back to the engine (see also tank vent).
Checking launch conditions
After turning off the engine, the necessary starting conditions are checked:
With a positive result, the diagnosis of a fuel tank leak begins with a comparative measurement.
Comparative measurement
After the engine is switched off, the fuel tank vent valve is always closed. The changeover valve of the diagnostic unit remains in the "Regeneration" position. An electric fuel tank leak detection pump draws air through a 0.5 mm gap. In this case, the value of the consumed current is memorized. The next step is to diagnose the leak.
Fuel tank leak diagnosis:
The fuel tank vent valve is still closed. The changeover valve of the diagnostic module moves to the "Diagnostics" position. The fuel tank leak detection pump draws air from the atmosphere into the fuel tank. In this case, the pressure in the tank slowly builds up. By the beginning of the leak diagnosis, the internal pressure corresponds to atmospheric pressure. Therefore, the current consumption is not large. As the pressure inside the tank increases, the current consumption increases. The current consumption of the leak diagnosis pump is analyzed in the DME.
Pump Current Estimation
The DME analyzes the increase in current consumption over time.
If the current consumed during this time exceeds the value stored in the memory, then the power supply system is considered to be in good condition. The fuel tank leak diagnostic ends.
If the consumed current does not reach the value recorded in the memory, then the power system is considered faulty.
Diagnostics of a fuel tank leak allows you to distinguish between:
The corresponding fault code is stored in the DME fault memory. After that, the fuel tank leak diagnosis is completed.
Completing the Fuel Tank Leak Diagnosis:
The changeover valve returns to the "Regeneration" position. The inertial phase of the DME continues to perform other functions.
The fuel tank leak diagnosis can also be started using the BMW diagnostic system. In this case, all the processes described above take place.
We reserve the right to typographical errors, errors and changes.
BMW N62B44 engine
Characteristics of the N62B44 engine
| Production | BMW Plant Dingolfing |
| Engine brand | N62 |
| Release years | 2001-2006 |
| Block material | aluminum |
| Supply system | injector |
| Type | V-shaped |
| Number of cylinders | 8 |
| Valves per cylinder | 4 |
| Piston stroke, mm | 82.7 |
| Cylinder diameter, mm | 92 |
| Compression ratio | 10 10.5 |
| Engine volume, cc | 4398 |
| Engine power, hp / rpm | 320/6100 333/6100 |
| Torque, Nm/rpm | 440/3600 450/3500 |
| Fuel | 95 |
| Environmental regulations | Euro 3 |
| Engine weight, kg | 213 |
| Fuel consumption, l/100 km (for 745i E65) - city - track - mixed. |
15.5 8.3 10.9 |
| Oil consumption, g/1000 km | up to 1000 |
| Engine oil | 5W-30 5W-40 |
| How much oil is in the engine, l | 8.0 |
| Oil change is carried out, km | 7000-10000 |
| Operating temperature of the engine, hail. | ~105 |
| Engine resource, thousand km - according to the plant - on practice |
- 400+ |
| Tuning, HP - potential - no loss of resource |
600+ - |
| The engine was installed | BMW 545i E60 BMW 645i E63 BMW 745i E65 BMW X5 E53 Morgan Aero 8 |
Reliability, problems and repair of the BMW N62B44 engine
The next generation of the V-shaped figure eight N62B44, was released in 2001 as a replacement M62B44 and in comparison with the previous model had a number of fresh innovations such as Valvetronic and Dual-VANOS. In addition, environmental performance has been improved, power and torque have been increased.
The N62B44 used a new aluminum cylinder block, with a cast iron crankshaft, lightweight aluminum alloy pistons, forged connecting rods.
Cylinder head gaskets in 6 mm laminated steel. The cylinder heads are redesigned, the N62 uses the Valvetronic intake valve lift system, an improved system for changing the valve timing on the intake and exhaust shafts Bi-VANOS / Dual-VANOS. cast iron camshafts,phase 282/254, rise 0.3-9.85/9.7 mm).The diameter of the intake valves is 35 mm, exhaust 29 mm.
The timing drive uses a maintenance-free chain. Variable length intake manifold, maximum length used at low revs up to 3500 rpm. Engine management system N62 - Bosch DME ME 9.2
This power unit was used onBMW cars with index 45i.
Based on the N62B44, a younger 3.6-liter version was produced, called N62B36.
Replaced the 4.4-liter engine in 2006, which has been produced for several years N62B48 (N62TU), with a displacement of 4.8 liters and even more maximum power.
Problems and disadvantages of BMW N62B44 engines
1. Zhor oil. Problems with increased oil consumption on the N62 begin, as a rule, by 100 thousand kilometers and the valve stem seals are the cause. After another 50-100 thousand oil scraper rings die.
2. Swim speed. Rough engine operation is often associated with failed ignition coils. Check, change and the motor will work fine. Another reason: air leakage, flow meter, valvetronic.
3. Oil leaks. Most often, the crankshaft oil seal or the sealing gasket of the generator housing flows. Replace and the leaks will be gone.
Among other things, over time, catalysts are destroyed on N62 and their honeycombs get into the cylinders, the consequences are badass. Therefore, it is better to remove the catalysts and put flame arresters instead. So that there are as few problems as possible and the resource is as long as possible, you need not save on oil and gasoline, regularly service your N62B44 and your engine will bring a minimum of problems and maximum pleasure.
BMW N62B44 engine tuning
Compressor
The only adequate and really power-increasing way is to install a whale compressor. You buy the most stable and popular kit from ESS, put on a standard piston, change the exhaust to a sports one. At a maximum pressure of 0.5 bar, your N62B44 will put out about 430-450 hp. However, in light of current prices for BMW M5 E60 /M6 E63, building a powerful N62 is unprofitable in any way, it’s easier to buy a powerful car with a V10 right away.
The power unit of the N62B44 model appeared in 2001. It became a replacement for the engine under the number M62B44. The manufacturer is BMW Plant Dingolfing.
Compared to its predecessor, this unit has several advantages, namely:
- Valvetronic - control system for the phases of gas distribution and valve lift;
- Dual-VANOS - second replenishment mechanism allows you to control the intake and exhaust valves.
ATTENTION! Found a completely simple way to reduce fuel consumption! Don't believe? An auto mechanic with 15 years of experience also did not believe until he tried it. And now he saves 35,000 rubles a year on gasoline!
Also in the process, environmental standards were updated, power and torque increased.
This unit used an aluminum cylinder block with a cast-iron crankshaft. As for the pistons, they are lightweight, but also made of aluminum alloy.
The cylinder heads were developed in a new way. The power units used a mechanism for changing the height of the intake valves, namely Valvetronic.
The timing drive uses a maintenance-free chain.
Specifications
For the convenience of familiarization with the technical characteristics of the N62B44 power unit of a BMW car, they are transferred to the table:
| Name | Meaning |
|---|---|
| Year of issue | 2001 – 2006 |
| Block material | Aluminum |
| Type | V-shaped |
| Number of cylinders, pcs. | 8 |
| Valves, pcs. | 16 |
| Piston backlash, mm | 82.7 |
| Cylinder diameter, mm | 92 |
| Volume, cm 3 /l | 4.4 |
| Power, hp / rpm | 320/6100 333/6100 |
| Torque, Nm/rpm | 440/3600 450/3500 |
| Fuel | Gasoline, AI-95 |
| Environmental regulations | Euro 3 |
| Fuel consumption, l/100 km (for 745i E65) | |
| - city | 15.5 |
| - track | 8.3 |
| - mixed. | 10.9 |
| Timing type | Chain |
| Oil consumption, g/1000 km | up to 1000 |
| Oil type | Top Tec 4100 |
| Max oil volume, l | 8 |
| Filling volume of oil, l | 7.5 |
| Viscosity degree | 5W-30 5W-40 |
| Structure | Synthetics |
| Average resource, thousand km | 400 |
| Operating temperature of the engine, hail. | 105 |
As for the engine number N62B44, it is stamped in the engine compartment on the right suspension strut. A special plate with additional information is located behind the left headlight. The number of the power unit is stamped on the cylinder block on the left side at the junction with the oil pan.
Analysis of innovations
Valvetronic system. Manufacturers were able to abandon the throttle, while not losing the power of the power unit. This possibility was achieved by changing the height of the intake valves. The use of the system made it possible to significantly reduce fuel consumption at idle. It also turned out to solve the problem with environmental friendliness, exhaust gases comply with Euro-4.
Important: in fact, the damper has been preserved, but it always remains open.
The Dual-VANOS system is designed to change the phases of gas distribution. It changes the timing of the gases by changing the position of the camshafts. Regulation is done by pistons that move under the influence of oil pressure, influencing the gears. By means of a toothed shaft
Malfunctions in work
Despite the long service life of this unit, it still has weaknesses. If you neglect the rules of operation, the unit will not function correctly. The main faults include the following.
- Increased engine oil consumption. Such a nuisance occurs at the moment when the car approaches the mark of 100 thousand kilometers. And after 50,000 km, the oil scraper rings need to be updated.
- floating turns. The intermittent operation of the motor in many cases is directly related to worn ignition coils. It is recommended to check the air flow, as well as the flow meter and valvetronic.
- Oil leakage. Also a weak point is the leakage of oil seals or sealing gaskets.
Also, during operation, catalysts wear out, and honeycombs penetrate into the cylinder. The result is bullying. Many mechanics recommend getting rid of these elements and suggest installing flame arresters.
Important: to extend the life of the N62B44 device, it is recommended to use high-quality engine oil and 95th gasoline.
Vehicle options
The BMW N62B44 engine can be mounted on the following makes and models of vehicles:
Unit tuning
If the owner needs to increase the power of the BMW N62B44 power unit, then there is one reasonable way - this is mounting a whale compressor. It is recommended to purchase the most popular and stable one from ESS. The process is just a few steps.
Step 1. Mount on a standard piston.
Step 2. Change the exhaust to a sporty one.
At a maximum pressure of 0.5 bar, the power unit produces about 430-450 hp. However, with regard to finances, it is not profitable to carry out such a procedure. It is recommended to purchase immediately V10.
Compressor Advantages:
- ICE does not require modification;
- the resource of the BMW power unit is maintained with moderate inflation;
- speed of work;
- increase in power by 100 hp;
- easy to dismantle.
Compressor Disadvantages:
- there are not so many mechanics in the regions who can correctly install the element;
- Difficulties in acquiring a used part;
- difficult search for consumables in the future.
Please note: if you do not know how to mount the kit, it is recommended to contact a specialized service center. Employees of the service station will carry out this operation quickly and efficiently.
Also, the owner can carry out Chip tuning. It is used to improve the factory settings of the electronic control unit (ECU).
Chip tuning allows you to change the following indicators:
- increasing the power of the internal combustion engine;
- improvement of acceleration dynamics;
- reduced fuel consumption;
- fix minor ECU bugs.
The chipping process takes place in several stages.
- The motor control program is being read.
- Specialists introduce changes to the program code.
- Then it is poured into the computer.
Please note: manufacturers do not practice this procedure because there are strict limits on exhaust gas ecology.
Replacement
As for replacing the N62B44 power unit with another one, there is such an opportunity. Can be used like its predecessors: M62B44, N62B36; and newer models: N62B48. However, before installation, you need to get advice from qualified specialists, and also seek help in installing them.
Availability
If you have a need to purchase a BMW N62B44 engine, then this will not be difficult. This ICE is sold in almost every major city. Moreover, you can visit popular automotive websites and find the right product there at affordable prices.
Price
The price policy for this device is different. It all depends on the region. On average, the cost of a used contract ICE BMW N62B44 varies between 70 - 100 thousand rubles.
As for the new unit, its cost is about 130-150 thousand rubles.
