Reliability, problems and repair of the BMW N52B25 engine
Another 2.5-liter engine of the already new N52 series (which also included the N52B30), with an in-line layout and six cylinders. The N52B25 was introduced in 2005 as a replacement for the popular M54B25, and unlike past evolutions of the M-family, it is now a completely new engine. At the heart of the N52 is an even lighter magnesium-aluminum cylinder block, with a new lightweight SHPG and a redesigned crankshaft.
The N52B25 uses an updated cylinder head with the already familiar system for changing the valve timing on two shafts, or, more simply, double Vanos (Double-VANOS). In addition, the Valvetronic valve lift change system was added to the vanos, which increased output and fuel efficiency. The timing drive uses a chain, a DISA variable-length manifold is used at the inlet, the nozzles are installed in the cylinder head, the Siemens MSV70 engine management system.
This motor was used on BMW cars with the index 23i and 25i. The replacement for the N52B25 engine came out already 2 years after its start of production, in the face of the N53B25 and strangled versions of the N53B30, however, 2.5 liters. N52 was produced for a long time and was taken out of production only in 2011.
BMW N52B25 engine modifications
- N52B25U1 (2005 - 2008 onwards) - base engine strangled with an intake manifold, power 177 hp at 5800 rpm, torque 230 Nm at 3500-5000 rpm. For versions with index 23i.
- N52B25 (2009 - 2011 onwards) - a blown engine with a different intake manifold, 204 hp. at 6400 rpm, torque 250 Nm at 2750 rpm. For versions with index 23i.
- N52B25O1 (2005 - 2009 onwards) - the most popular version with 218 hp. at 6500 rpm, torque 250 Nm at 2750-4250 rpm. For versions with index 25i.
Problems and disadvantages of BMW N52B25 engines
- The biggest problem with the N52B25 is oil consumption. It's all about thin oil scraper rings, which quickly coke, as well as dead valve stem seals. Moreover, on the N52, such things can happen on runs up to 100 thousand km ... Check the condition, buy new caps and rings. It will not be superfluous to check the condition of the crankcase ventilation valve (CVKG). The problem has been solved on motors since 2007, called N52NB25 (black cap).
- If you spit on the high oil consumption and continue to drive as is, then a little later the catalysts begin to clog. Solution: A. Buying new catalysts is expensive. B. Buy flame arresters, it's cheap.
- Ticking sound. It manifests itself in the cold and is a feature of production engines until 2009. There are no negative consequences for the motor from this.
- Floating turnovers. Such problems are usually associated with Valvetronic, flow meter or Vanos valves. On the N52, vanos quite often causes problems due to improper maintenance (oil change every 20 thousand km, use of low-quality oil). Vanos repair is simple: first flush the vanos valves, if the problem persists, then replace. Check. In addition, the engine is very prone to overheating, you need to constantly monitor the cooling system, the cleanliness of the radiator, the H52 uses a not very durable electronic pump that needs to be replaced every ~ 80-100 thousand km. To reduce the likelihood of various troubles, oil in the N52 engine it is recommended to pour high-quality, recommended by the manufacturer, it is also not worth saving on gasoline; also, the auto technical center is engaged in changing the oil in a BMW engine.
Characteristics of the N52B25 engine
| Production | Munich Plant |
| Engine brand | N52 |
| Release years | 2005-2011 |
| Block material | magnesium aluminum |
| Supply system | injector |
| Type | in-line |
| Number of cylinders | 6 |
| Valves per cylinder | 4 |
| Piston stroke, mm | 78.8 |
| Cylinder diameter, mm | 82 |
| Compression ratio | 11 |
| Engine volume, cc | 2497 |
| Engine power, hp / rpm | 177/5800 204/6400 218/6500 |
| Torque, Nm/rpm | 230/3500-5000 250/2750-3000 250/2750-4250 |
| Fuel | 95 |
| Environmental regulations | Euro 5 |
| Engine weight, kg | ~120 |
| Fuel consumption, l / 100 km (for E60 523i) - city - track - mixed. |
12.1 6.4 9.3 |
| Oil consumption, g/1000 km | up to 1000 |
| Engine oil | 5W-30 5W-40 |
| How much oil is in the engine, l | 6.5 |
| When replacing pour, l | ~6.0 |
| Oil change is carried out, km | 10000 |
| Operating temperature of the engine, hail. | ~95 |
| Engine resource, thousand km - according to the plant - on practice |
- |
| Tuning, HP - potential - no loss of resource |
280+ n.a. |
| The engine was installed | BMW 323i E90 BMW 325i E90 BMW 523i E60 BMW 525i E60 BMW 523i F10 BMW X3 E83 BMW Z4 E85 BMW Z4 E89 |
BMW N52 series engines have replaced the outdated M54 engines. The new motor received practically nothing from its older brother. Everything has been changed, from materials for the execution of parts to design features. Only maintenance remained unchanged.
Characteristics and features of motors
The BMW N52 engine received an improved lightweight magnesium-aluminum cylinder block. The crankshaft was structurally modified for the new block. Gas distribution drive - chain.
The new cylinder head, in which a variable valve timing system is installed on two shafts, or, more simply, double Vanos (Double-VANOS). In addition, the Valvetronic valve lift system was added to the VANOS, which increased the output and fuel efficiency.
Consider the main technical characteristics of the N52:
| Name | Characteristics |
| Manufacturer | Munich Plant |
| Motor brand | N52 |
| engine's type | Injector |
| Volume | 2.5 liters (2497 cc) |
| Power | 177-218 hp |
| Cylinder diameter | 82 |
| Number of cylinders | 6 |
| Number of valves | 24 |
| Torque | 230/3500-5000 250/2750-3000 250/2750-4250 |
| Compression ratio | 11 |
| Economy | Euro 5 |
| Fuel consumption | 11.3 liters for every 100 km in mixed mode |
| Engine oil | 5W-30 5W-40 |
| Resource | 250+ thousand km |
| Applicability | BMW 323i E90 BMW 325i E90 BMW 523i E60 BMW 525i E60 BMW 523i F10 BMW X3 E83 BMW Z4 E85 BMW Z4 E89 |
N52 engine
Motor modifications
In addition to the standard configuration, there are a number of modifications of the power unit, which made it possible to install it on different models of BMW cars:
- N52B25U1 (2005 - 2008 onwards) - base engine strangled with an intake manifold, power 177 hp at 5800 rpm, torque 230 Nm at 3500-5000 rpm. For versions with index 23i.
- N52B25 (2009 - 2011 onwards) - a blown engine with a different intake manifold, 204 hp. at 6400 rpm, torque 250 Nm at 2750 rpm. For versions with index 23i.
- N52B25O1 (2005 - 2009 onwards) - the most popular version with 218 hp. at 6500 rpm, torque 250 Nm at 2750-4250 rpm. For versions with index 25i.
Replacing Timing N52
Service
Maintenance of N52 motors is no different from standard power units of this class. Maintenance of engines is carried out at intervals of 15,000 km. Recommended maintenance should be carried out every 10,000 km.
The process of changing the oil in the N52
Typical malfunctions
In principle, all motors are similar in design and characteristics. This series of engines had enough problems, after which it was decided to stop the production of power units. So, let's look at what common problems can be found on the N52:
N52 motor repair
- Like all BMWs, the big problem is increased oil consumption. In this series of motors, the oil scraper rings are thin, which leads to engine oil consumption.
- High fuel consumption. The solution is to replace the catalyst or install flame arresters.
- floating turns. It is worth checking the flow meter or VANOS valve.
- Well, the last common problem is overheating. We change the thermostat, see if there are any coolant leaks, and then we rejoice at the operation of the motor.
Conclusion
The N52 engine is a fairly reliable and high-quality engine. All of them have a high rating and respect of motorists, experts. Maintenance of the power unit can be carried out independently. This series has a number of shortcomings, which did not allow the power unit to successfully take root.
The atmospheric six-cylinder N52 engine was first delivered to BMW back in 2004. The new unit replaced the heavier (10 kg) and less powerful (27 hp) M54 engine. However, innovations related to the use of the Valvetronic system and the use of magnesium and aluminum in the crankcase have had an ambiguous effect on the reliability of the BMW N52 engine.
Typical BMW N52 Engine Problems
Among all types of breakdowns associated with the N52 engine, we most often encounter the following in GR CENTR:
- Hydrocompensation system. The problem usually manifests itself after 80,000 km. run when starting a cold power unit: extraneous sounds appear (ticking, rustling). After the engine warms up, the noise disappears. Cause of the malfunction: the hydraulic compensation system does not receive enough oil without admixture of air. There is no real danger in this case, however, it is worth carefully warming up the power unit before operating it in operating mode.
- Crankcase ventilation valve. The valve membrane that dries up over the years breaks, as a result, air, dust and sand freely enter the motor. It is fraught with increased wear of components and parts.
- Piston rings. Their insufficient thickness and unsuccessful shape lead to rapid wear, as a result of which oil consumption increases significantly.
Entrust the repair of BMW N52 engines to professionals
We provide professional services related to the repair of BMW N52 engines in Moscow. Moreover, in our center it is possible to solve almost any problem related to BMW cars.
Come to the address: Ryazansky prospect, vl. 39-A or call the phone number listed in the header of the site right now!
The Moscow technical center Sport KB offers a service: engine repair N52 BMW 323i, 325 (E90), 523i, 525i (E60), 523i (F10), X3 (E83), Z4 (E85, E89). We carry out scheduled, urgent or major repairs of BMW engines, regardless of the degree of complexity.
What is included in the repair of the N52 engine
Our specialists carry out such types of maintenance and repair as:
- replacement of the BMW N52 fine fuel filter;
- replacement (KVKG) BMW N52;
- repair of hydraulic lifters;
- replacement of valve seals (MSK) BMW N52 (without removing the block head and with removing the cylinder head);
- BMW N52 cooling system repair (pump replacement, radiator flushing);
- replacement of the BMW N52 timing drive repair kit (rollers, belt);
- flushing BMW N52 injectors;
- repair and adjustment of the Valvetronic system;
- repair of the Vanos system (replacement of sealing rings, repair of the drive);
- repair of the BMW N52 cylinder-piston group (replacement of spark plugs);
- overhaul of the BMW engine (N52).
BMW N52 engine
The main "weak points" of the BMW N52 engine and its modifications (N52B25U1, N52B25, N52B2501) are hydraulic compensators, a pump, a Valvetronic system drive and a catalyst. BMW N52 engines are demanding on the quality of the engine oil used for them and are sensitive to a decrease in its level. In the case of a rare oil change and the use of low-quality lubricants, the highly loaded parts of the BMW N52 engine begin to experience “oil starvation”.
Common malfunctions of the BMW N52 engine with a range of 80 to 100 tons:
- the crankcase ventilation valve is clogged;
- valve stem seals lose their elasticity and crack;
- oil scraper piston rings are clogged with soot deposits, and "lie down".
A sign of this malfunction is mainly a significant increase in oil consumption, a decrease in engine power, bluish-gray smoke from the muffler.
If your BMW engine starts to leak oil, starts worse, its power and throttle response have decreased, and the consumption of gasoline and oil has increased - contact Sport KB! Our experts will quickly and inexpensively eliminate all malfunctions.
Photos from repair zone
The N52 and N52N engines are a fundamentally new generation of BMW engines, which went into production in 2004. The power unit is “hot”, both in terms of temperature control and due to the dense layout of the engine compartment. - a rather laborious process, which we will discuss in this article.
The N52 engine was produced between 2004 and 2011.
Design features
Compared to previously produced engines, the N52 has been modernized. The following design improvements have been made:
- oxygen sensors have become broadband;
- changing the length of the intake manifold occurs in two stages;
- the crankcase ventilation valve has become more reliable;
- the design uses a variable displacement oil pump;
- added Valvetronic air supply system.
To reduce the weight of the engine, some of the components are made of magnesium. To protect the material from corrosion and cracking, aluminum is additionally used. So, the outer shell of the crater is made of magnesium, and the inner part is made of aluminum. Cylinder liners are also made from it.
Main problems and malfunctions
Under the condition of standard operation of the car, the service life of the motor is 150-180 thousand km. In practice, it may be required much earlier. The problem nodes and parts of the N52 are:
- Hydrocompensation system. A typical malfunction for motors that were produced before November 2008. It consists in the appearance of a ticking sound after 80 thousand kilometers at the time of starting a cold engine. After warming up the power unit, the rustling or characteristic ticking disappeared. The reason is that the elements of the hydraulic compensation system of such a power unit do not receive the required amount of oil without air content. This does not pose any danger to the engine, however, dealers advised to thoroughly warm up the engine, and only then give workloads. The solution was the release of power units equipped with a new design cylinder block cover.
- Crankcase ventilation valve. Over time, the valve membrane dries out and breaks, and as a result, air begins to enter the motor. This causes unstable operation of the power unit, accompanied by "sneezing". In addition, dust and sand enter the engine along with the air. As a result, the intensity of wear of parts and assemblies increases. This problem is typical for both the N52 engine and its modifications, including the N52N. At the same time, the design of the N52N engine is such that the KVKG is built into the valve cover, therefore, when repairing, the entire assembly is replaced.
- Piston rings. An increase in oil consumption is often associated with the occurrence and wear of piston rings. In particular, in engines with a volume of 2.5 liters, they are too thin and do not differ in the most successful shape. As a result, they wear out ahead of time, and, as a result, the car owner gets a car that consumes up to 1 liter of oil per 1000 km.
Another problem is the electronic oil level sensor. He often fails and either refuses to work at all, or gets confused in the testimony. And with an increased appetite of the engine, this is fraught with oil starvation and serious breakdowns.
In general, it is worth noting that the N52 and N52N engines are demanding on the quality of the oil, therefore, only premium brands recommended by the manufacturer should be used for replacement.
Sectional view of the N52 engine block.
Expert opinion
Car owners often ask about the service life of engine components and parts. I answer:
- replacement of valve stem seals is carried out after 80-100 thousand km, while on standard oil the working life can reach 150 thousand km;
- crankcase ventilation valve serves 3 years or 100 thousand km;
- the service life of belts and rollers is 60-85 thousand km;
- the pump serves 90-120 thousand km;
- the fuel filter in the N52 and N52N engines, according to the regulations, is changed after 60 thousand km.
As for the maintenance of N52, it is worth noting the need for the following procedures:
- antifreeze is replaced once every two years or every 60 thousand kilometers;
- every 30-50 thousand kilometers you need to flush the nozzles at the stand;
- after the same run, the candles change;
- pay attention to the vanos check valves, the nets of which are often clogged and do not allow oil to pass through;
- to avoid overheating, you should regularly wash the radiator, especially since this procedure is inexpensive, and on average, cleaning costs 3,500 thousand rubles.
The Vanos valves in the N52 engine can become clogged, resulting in oil starvation.
Untimely and irregular maintenance of the engine leads to serious breakdowns, which cause significant financial losses. For example, oil starvation turns into a replacement or overhaul of the engine. It costs about 300 thousand rubles. And if the valve burned out, the repair will cost 150 thousand, and this is at best when there are no scuffs in the cylinder block and the cylinder head did not drive.
And finally, one more piece of advice. A sharp peak load on the engine, including when jerking from a traffic light, leads to chain stretching and the need to replace it. Practice a calm driving style and perform regular maintenance using diagnostic equipment. This will prolong the life of the car and save you money.
