Among motorists there are stories about German engines, whose mileage was more than 1 million kilometers, and there are many confirmations of this. If you ask auto mechanics which engine is the most reliable and durable, most of them will answer that these are German BMW and Mercedes-Benz engines. To the list of advantages should be added a surprisingly lively disposition and not a high appetite. Consider the German BMW M40B18 engine, its technical characteristics, pros and cons.

Main characteristics

• produced from 1987 to 1994 inclusive;
• the cylinder block is made of cast iron, so this motor weighs the same as six-cylinder with an aluminum block;
• fuel supply is carried out by an injection system;
• four cylinders, each with two valves;
• the piston travels vertically 81 mm;
• the cylinder has a diameter of 84 mm;
• the engine runs at a compression ratio of nine units;
• the exact volume of the unit is 1796 cubic centimeters;
• the motor produces 113 horsepower at its peak;
• torque is 162 Nm at peak power;
• feeds on ninety-second gasoline;
• does not comply with any environmental standards;
• weighs, as already mentioned, a lot. Approximately one hundred and thirty-two kilograms;
• consumes a lot for its low power: more than ten liters in the city, about seven on the highway and eight to nine in mixed mode;
• oil consumption is high. It can reach a thousand grams per one thousand kilometers;
• oil to be poured into the engine: 5W-30; 5W-40; 10W-40; 15W-50;
• about four liters of oil in the engine;
• it needs to be replaced every seven to ten thousand kilometers;
• works at a temperature of ninety - one hundred degrees;
• the resource is not indicated by the plant, but in practice it is more than three hundred thousand kilometers;
• by forcing you will reach a little over one hundred and fifty horsepower;
• was installed on the BMW of the Fifth and Third series with the index 18i.

Engine Description

The BMW M40B18 four-cylinder engine replaced the old M10. It has hydraulic lifters, so the valves do not need such frequent adjustment. Here, unlike the six-cylinder BMW engines of that time, a timing belt is used, it is unreliable and fails along with its roller every forty to forty-five. If this belt breaks, the valves will be bent, and this will already entail large investments.

Cons of this engine

1. The engine may knock. The cause is most often already unusable camshafts, hydraulic lifters or rocker arms. They need to be checked first;
2. floating turns. The mass air flow sensor has an air duct. If there is a leak or any damage, then you must repair it (them);
3. The engine starts to fail. The reason is injectors. If they are dirty, then they need to be cleaned;
4. Overheating. The reason may be the cooling system, or rather one or more of its elements. Thermostat, pump, radiator. It may have plugs. So try to bleed the air;
5. Can't start. The problem may be: fuel pump, spark plugs, high voltage wires and ignition coil.

Forcing

You should immediately understand that tuning this engine is very unprofitable. It's easier to get an M50 and replace that four-cylinder baby. But if you still dare, you can try the stroker. You can boost up to 2.1 liters with an M47D20 elbow, S50B30 pistons and M44B19 connecting rods. Everything else (inlet, outlet, cylinder head and timing) from the M44. All these machinations will give you 150-160 horsepower. It is simply impossible to install a turbine or compressor, because. it is very expensive and difficult, especially for such an ancient engine.

Introducing a technical review of the BMW M40 engine

Description

The BMW M40 is an in-line gasoline four-cylinder eight-valve engine with a direct cylinder arrangement. Only two modifications were produced with a working volume of 1.6 and 1.8 liters. On BMW cars of the fifth series, only the last option, the M40B18, was used.

The BMW M40 became the successor and replacement of the M10 engine, while maintaining reliability and gaining new advantages. Like its predecessor, the M40 has a cast-iron cylinder block, but oil hydraulic compensators appeared in the aluminum block head. Also, the designers replaced the camshaft chain drive with a belt drive. The same belt rotates the air-cooled drive. This allowed to significantly reduce engine noise.

Carburetor injection was replaced by injection, which allowed not only to reduce fuel consumption, but also to improve acceleration dynamics.

Many motorists fell in love with the BMW M40 for its low noise level, relative efficiency and ease of maintenance.

Specifications

FlawsM40 engine

However, the M40 also has its drawbacks. The first one is the most obvious and concerns rather not the engine itself, but the engineering decision to install it on the fifth series BMW models. For a fairly heavy business class car, the M40B18 engine turned out to be rather weak.

The purely technical disadvantages include the insufficient strength of the timing belt.

A broken timing belt is fraught with damage not only to the valves, but also to the pistons. To prevent adverse consequences, the timing belt must be replaced every 40 thousand kilometers. The belt should be changed along with the roller.

The engine has an imperfect cylinder head lubrication system. Therefore, the rapid wear of timing parts is a frequent problem.

The connections of the pipes of the cooling system are short-lived, and their depressurization entails an increased consumption of antifreeze.

Another disease of the BMW M40 engine is a malfunction of the lambda probe, which can be determined by an increase in gas mileage and speed surges.

In general, the M40 engine has shown itself to be quite reliable, and the listed problems, as a rule, come to naught in case of careful operation and observance of maintenance periods.

!!

BMW produced M40 engines of 1.8 and 1.6 liters. This power plant was installed on the models of the third series and replaced the BMW M10 engine. The engine change coincided with the E30 body update. The M40 engine was released in 1987 and was produced until 1995, but since 1993 the e36 body has already been produced with the new M43 unit.

Technical characteristics of the BMW M40 engine

- This is a cast-iron 4-cylinder engine with an aluminum block head with one camshaft, belt drive and 8 valves. According to experts, the M40 has become less reliable compared to the M10 (for example, when the belt breaks, the valves bend, the pistons break through and cracks form), but at the same time it has become elastic and quieter. Another problem should be called oil starvation of parts that rub - this leads to their wear and overheating.

BMW M40 V16 engine

The BMW M40 B16 engine is a 1.6 liter version. The power of the installation is 102 hp. at 5800 rpm, while the maximum safe rate for the motor is 6200 rpm. The maximum engine torque - 141Nm is reached at 4250 rpm. This motor uses a Bosch M 1.3 injection power system. The cylinder diameter is 84mm, with a piston stroke of 72mm and a compression ratio of 9. This engine model was installed on the BMW E30 316i from 1988 to 1995 and on the BMW E36 316i from 1990 to 1994.

1987 was marked by the appearance of the BMW M40 B018 engine, it was installed on the 318i model in the back of the e30, and since 1988, the 316i e30 was equipped with a smaller engine. Starting in 1990, the BMW M40 engine was also installed on the e36 model, it was equipped with the 316i and 318i models. And the BMW 5 series, which was equipped with the M40 engine, appeared in 1988 and was equipped with this unit until 1994.

BMW M40 B18 engine

The BMW M40 B18 engine is a 1.8 liter version of the power plant with a power of 115 hp, the revolutions of which are 5500 per minute, while the maximum safe rate for the engine is 6200 rpm. The maximum engine torque of 165 Nm is reached at 4250 rpm. This motor uses a Bosch M 1.3 injection power system. The engine is equipped with 84mm cylinders, with a piston stroke of 81mm and a compression ratio of 8.8. 1988 to 1994).

BMW M40B18 engine

Characteristics of the M40V18 engine

Production	Steyr Plant
Engine brand	M40
Release years	1987-1994
Block material	cast iron
Supply system	injector
Type	in-line
Number of cylinders	4
Valves per cylinder	2
Piston stroke, mm	81
Cylinder diameter, mm	84
Compression ratio	9
Engine volume, cc	1796
Engine power, hp / rpm	113/5500
Torque, Nm/rpm	162/4250
Fuel	92
Environmental regulations	-
Engine weight, kg	~132
Fuel consumption, l/100 km (for 318i E30) - city - track - mixed.	10.3 6.7 8.6
Oil consumption, g/1000 km	up to 1000
Engine oil	5W-30 5W-40 10W-40 15W-50
How much oil is in the engine, l	4.0
Oil change is carried out, km	7000-10000
Operating temperature of the engine, hail.	90-95
Engine resource, thousand km - according to the plant - on practice	- 300+
Tuning, HP - potential - no loss of resource	150+ n.a.
The engine was installed

Reliability, problems and repair of the BMW M40B18 engine

The first in-line four-cylinder engine of the M40 family, the older brother, developed in 1987 as a replacement for the outdated M10 series. The engine is based on a cast-iron cylinder block covered with an 8-valve head with one camshaft and hydraulic lifters (valve adjustment is not required on the M40). The diameter of the intake valves is 42 mm, exhaust 36 mm. Characteristics of BMW M40 camshafts: phase 244/244 rise 10.6/10.6 mm.
The timing drive uses an unreliable belt that requires constant monitoring and replacement along with the roller, on average, once every 40 thousand km. With a frivolous attitude to this problem, the risk of breaking the timing belt and bending the valves increases.
This motor was used on BMW cars with the 18i index.
In parallel with the M40B18, since 1989 a more powerful version of the 1.8 liter engine has been produced - for sports 18i.
In 1992, a changer for the M40 engine was released, it became an updated one.

Problems and disadvantages of BMW M40B18 engines

1. Engine knock. Often the fault of various M40 noises lies on a worn camshaft, rocker arms and hydraulic lifters. Check.
2. Swim speed. Check the air duct on the DMRV for integrity, there may be air leaks. Next, we inspect the DMRV, lambda probe, the state of the throttle and KXX. In addition, the M40 speed problem is also hidden in the difficult rotation of the camshaft.
3. Dips during acceleration. The main reason for the dullness of the engine is the injectors, most likely they require cleaning.
4. Overheating. The search for the cause must begin with an inspection of the condition of the radiator, pump, thermostat, checking the cooling system for plugs, checking the condition of the plastic tubes of the cooling system.
5. Won't start. Look for a problem in the fuel pump, spark plugs, high voltage wires, ignition coil.
Do not forget about the well-known problem with the not very reliable timing belt described above. Add to this the age of the motor and the output is not the best acquisition.
The BMW M40 engine itself is reliable, its resource is about 300 thousand km, in some cases more is possible. However, almost all BMW M40B18 to date have crossed this mark and trouble-free operation, most likely, can be forgotten.

The reliable and simple long-lived M10 has been replaced by the new BMW M40 four-cylinder petrol engine. The purpose of the engine was, first of all, for BMW 3-series cars. He updated the engine compartment of the BMW E30. However, later, the motor found application in the 5th. Fans of fast driving note the low power of the engine for BMW cars of the fifth series, which is heavier than triplets. The release was limited to only two volumes - 1.6 and 1.8 liters. The first M40 engine rolled off the production line in 1987, and production continued until 1995. From its predecessor, he inherited a cast-iron cylinder block (cast from gray cast iron). There is a possibility of boring cylinders for repair dimensions. Eight counterweights balance the work of a solid crankshaft. The drive of the gas distribution mechanism has become a belt, and the adjustment of thermal gaps is carried out by oil hydraulic compensators. The novelty has become much quieter in operation compared to its older brother. The cooling water pump is driven by the timing belt. The engine exhaust valves are filled with sodium to reduce heat. The oil pump is gear type, driven by the crankshaft of the engine. The cylinder head is made of aluminium. The camshaft is one for the 4th cylinder, controls 8 valves. The cam is pressed on the hydraulic compensator not by direct contact, but through a rocker. Metal intake manifold. The crankcase ventilation system is natural. The simplicity of design and the availability of repairs have won their fans. Relative efficiency compared to other BMW engines has become another important factor when choosing a car. Despite the 4th cylinder vivacity of revs is present. The carburetor has been replaced by an injection system, which further confirms the economy and agility of a small engine. Owners note very good throttle response for a 4-cylinder engine. The flywheel on the crankshaft is monolithic. The eight-bladed radiator cooling fan is driven through a viscous coupling. The ignition system is distributed. The weight of the M40 engine is about 81 kg.

Problems

As for the features, you should monitor the condition of the timing belt. It is thinner and looks more flimsy than the six-cylinder M20 engine. A break can lead not only to the curvature of the valves, but also to breakage of the pistons. The valves usually do not bend, half can remain intact. It is recommended to replace the timing belt no later than 40 thousand km. along with the roller. The M40 engine has a not entirely successful lubrication system in the cylinder head. Lack of oil leads to premature wear of hydraulic lifters and rocker arms. Valve clatter under the hood of a car is a common engine problem. Cracks in the air duct between the throttle and the air mass meter are a common malfunction of BMW M40 engines. The plastic flanges of the cooling system eventually become unusable and begin to leak antifreeze. Loss of coolant leads to inevitable overheating. Unstable operation and increased fuel consumption may be due to a malfunction of the lambda probe, which is very common. Typical distributed ignition problems are faulty spark plugs, high voltage wires, ignition coil, and others. Wear of the cam-rocker interface is inevitable over time. It manifests itself primarily at high speeds, when the cylinder is turned off. Erratic operation can be caused by air being sucked in through aged seals. The use of low-quality oil causes tarry deposits on the oil channels of parts and assemblies. Oil starvation leads to premature overhaul or part replacement. Blue smoke from the exhaust pipe and increased oil consumption may be due to wear on the timing valve stem seals. The duration of production confirms the reliability of the four-cylinder engine and the well-deserved trust among car buyers.

M40B16 engine

It has a volume of 1596 cc. It was produced with a power of 100 and 102 hp. The Motronic injection system in 1991 for the E36 body was changed to a newer one. The cylinder diameter is 84 mm and the piston stroke is 72 mm.

The M40B16 engine is installed on the following vehicles:

• 1988-1994 BMW 316i (E30 body)
• 1990-1994 BMW 316i (E36 body)

M40B18 engine

Engine capacity - 1796 cc. Engine power -113 hp For the body, the E36 differed only in the injection system. The cylinder diameter, like that of the 1.6-liter engine, is 84 mm, and the piston stroke is increased to 81 mm.

The M40B18 engine is installed on the following vehicles:

• 1987-1994 BMW 318i (E30 body)
• 1988-1994 BMW 518i (E34 body)
• 1992-1993 BMW 318i (E36 body)