The naturally aspirated six-cylinder N52 engine was first introduced to BMW back in 2004. The new unit was replacing the heavier (10 kg) and less powerful (27 hp) M54 engine. However, the innovations associated with the use of the Valvetronic system and the use of magnesium and aluminum in the crankcase have 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, the most common in GR CENTR are the following:
- Hydraulic compensation system. The problem usually appears 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 malfunction: the hydraulic compensation system does not receive enough air-free oil. There is no real danger in this case, but it is worth carefully warming up the power unit before operating it in operating mode.
- Crankcase ventilation valve. The valve membrane, which dries out over the years, breaks, as a result, air, dust and sand freely enter the motor. It is fraught with increased wear of units and parts.
- Piston rings. Their insufficient thickness and poor shape lead to rapid wear, as a result of which oil consumption is significantly increased.
Entrust BMW N52 engine repair 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, ow. 39-A or call the phone number listed in the site header right now!
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When you read specialized articles on the piston group, you always note the highest level of technical unrestrained thought of the authors' imagination: it seems that every unit of a car, a piston, for example, is the fruit of many years of non-stop torment of engineers. They tirelessly fight over them from the beginning of the last century to the present day. Well, purely like motor oil: synthesis of molecule by molecule by hand.
So you can imagine that a designer of a submarine and some designer-technologist of foundry will meet like this ... One super-secret nuclear submarine of special secrecy and low visibility is designing, the second is pouring pistons. They will look at each other and be meaningfully silent, filled with great mystery. Both from the height of technical inaccessibility look blissfully at mere mortals.
Today we will talk about why submarines sink and surface, planes fly and land, and the engine N52B25 continues to eat butter.
To begin with, let's consider how technical thought, so to speak, piston construction, progresses from the beginning of the century to the present day:
Here is the standard piston of a car from the turn of the century:
And here is the progressive pre-war design: 
Post-war European, already noticeably forced subcompact "piston school": 
Russian-Soviet products ... in fact - all the same subcompact-European, Italo-fascist-German: 
All the differences are in terms of weight and dimensions - the further, the smaller and lighter all the components. Some exception - many purely American motors are low-speed, with classic heavy pistons. European ones - for relatively small engine displacement and high revs - are lightweight.
Of course, there is a lot of all kinds of husks around like graphite antifriction coatings on the skirt, special hardened grooves, improved rings and exquisite oil drainage grooves. In reality, the piston of a correctly calculated block should not touch the cylinder walls at all: not during shifting, nor in any imaginable mode, except for emergency, of course. That is, literally never at all. Will touch - no cover will save him. The same is with the shape, profile and coating of the rings: with a normal calculation of stiffness, it is chrome-plated, or nitrided, or a combination of both on one piston - it does not matter in principle. Therefore, for example, "NK" is still doing chrome plating, "Goetze" - nitriding, and the original can be a combination of both technologies from "Mahle" ...
The modern piston is most often the so-called. barrel profile: (---).
To check this, we set absolute zero on the piston bottom and sequentially check the diameters by conditional points,
moving down along its lateral surface: 
Something like this looks like the profile of this surface based on the results of ten measurements: 
Smoothing this data gives the following picture of the surface profile: 
Remember what the section from 1 to 5 looks like - this is the heat and sealing belts of the piston.
We draw the obvious conclusion that the greatest deviations in geometry are observed just in the area of \u200b\u200bthe top and sealing belts.
It is logical that it is "hot" because it gets a lot of heat from the combustion chamber - there is some reserve for thermal expansion.
So, in fact, the engine pistons are / - \\ rather than (-).
Now let's move on to really progressive designs. No quotes. If conventions aside, then truly modern,
lightweight, you can call the T-shaped pistons of the new generation "N" engines from BMW.
For example, N52B25, produced since 2005.
Let's compare it with the VAZ sample from the VAZ-2112 (BMW - on the right), keep in mind that their diameters are the same: 
The new generation of pistons from BMW differs markedly from everything that has been produced for the last 100 years: the piston has
ultra-low profile, miniature piston rings, and sophisticated bottom contours for a high compression ratio of 11: 1.
The problem, as you know, is that the early N52B25 engines had a strange tendency to consume oil.
from the very beginning of operation, which BMW guessed only by 2010:
The new pistons have a new, "external" oil drainage and a "heat-resistant insert" in the area of \u200b\u200bthe upper compression ring: 
Given that the piston skirt and all the main measurement points are absolutely the same, the difference should be sought in the area of \u200b\u200bthe sealing belt: 
We install the micrometer and make sure that the upper compression ring is "dropped" by as much as 156 microns! This is about 0.16 mm, with a general factory tolerance for the gap for ultimate wear of 0.15 mm. And this is the new piston! Moreover, the piston profile itself is clearly "unhealthy", with a pronounced abnormal dip. With a constant depth of the piston groove, this means that the piston swings in the cylinder "by hand" - the upper ring holds it weakly: 
Now we subject the pistons of two samples to thermal expansion: 
And we carry out repeated measurements: 
We measure the leak in a completely rebuilt N52B25 engine with new liners, rings, a new cylinder head, but
with old-style pistons:
There is no doubt. This engine has consumed and will continue to consume oil until the installation of new pistons.
1.Who is to blame?
Early pistons on the N52B25 engine have a serious upper compression ring problem. It quickly "sinks" in the castle,
loses its elasticity and initially (from the factory) sits too loosely in the cylinder. The oil is easily squeezed into the combustion chamber. Replacing only rings with new ones
won't help you.
2. What to do?
Buy a new piston group with a fixed problem.
3. Attention, for the owners of N52B25 I announce a special offer to eliminate this problem. Works indefinitely.
Diagnostics of this ICE model (up to 2011) under special conditions - 25%. Only valid when linked to this ad.
Work on replacing a piston internal combustion engine - 60,000 rubles.
If you have already passed the diagnostics of this internal combustion engine with me earlier, and also performed work on the cylinder head - for you a special offer on individual conditions.
This strange motor drank a lot of blood. We need to make everyone happy.
Engines of the BMW N52 series replaced the outdated M54 engines. The new motor received almost nothing from its older brother. Everything has been changed, from the materials of the parts to the design features. Only maintenance remained unchanged.
Characteristics and features of motors
The BMW N52 engine has received an improved lightweight magnesium-aluminum cylinder block. The crankshaft has been structurally changed for the new block. Gas distribution drive - chain.
A new cylinder head, in which a variable valve timing system is installed on two shafts, or, more simply, a double Vanos (Double-VANOS). In addition, the Valvetronic valve lift system has been added to VANOS, which improves efficiency 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 |
| Econorm | Euro 5 |
| Fuel consumption | 11.3 liters for every 100 km of run 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 equipment, 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) - the base engine strangled by the intake manifold, 177 hp at 5800 rpm, torque 230 Nm at 3500-5000 rpm. For versions with index 23i.
- N52B25 (2009 - 2011 onwards) - a bloated 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 the timing belt N52
Service
Maintenance of N52 motors is no different from standard power units of this class. Engine maintenance is carried out at intervals of 15,000 km. The recommended service is required every 10,000 km.
Oil change process in N52
Typical malfunctions
In principle, all motors are similar in design and performance. This series of motors had enough problems, after which it was decided to discontinue the production of power units. So, let's take a look at what common problems can be found on the N52:
Repair of the N52 motor
- Like all BMWs, the big problem is the increased oil consumption. In this series of motor, the oil scraper rings are thin, which leads to engine oil burn.
- High fuel consumption. The solution is to replace the catalyst or install flame arresters.
- Floating revolutions. 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 rejoice at the operation of the engine.
Conclusion
The N52 engine is quite reliable and high-quality engines. They all have a high rating and respect from motorists and experts. The power unit can be serviced by yourself. This series has a number of disadvantages that did not allow the power unit to successfully take root.
The Moscow technical center Sport KB offers the 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 overhaul of BMW car 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 repairs as:
- replacement of the fine fuel filter BMW N52;
- replacement (KVKG) BMW N52;
- repair of hydraulic lifters;
- replacement of valve seals (MSC) BMW N52 (without removing the head of the block and removing the cylinder head);
- repair of the BMW N52 cooling system (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 O-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 "weaknesses" of the BMW N52 engine and its modifications (N52B25U1, N52B25, N52B2501) are hydraulic lifters, 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 poor quality lubricants, the heavily loaded parts of the BMW N52 engine begin to experience "oil starvation".
Common malfunctions of the BMW N52 engine with a mileage of 80 to 100 t. Km:
- the ventilation valve of the motor crankcase is clogged;
- valve stem seals lose elasticity and crack;
- the oil scraper piston rings are clogged with soot deposits, and "stuck".
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 leaking oil, starts up worse, its power and throttle response has decreased, and the consumption of gasoline and oil has increased - contact Sport KB! Our specialists will quickly and inexpensively eliminate all faults.
Photos from the workshop
BMW N52B25 engine reliability, problems and repair
Another 2.5-liter engine of the already new N52 series (which also includes the N52B30), with an in-line layout and six cylinders. Introduced the N52B25 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 modified crankshaft.
The N52B25 uses an updated cylinder head with the already familiar variable valve timing system on two shafts, or, more simply, Double-VANOS. In addition, the Valvetronic valve lift system was added to the vanos, which increased efficiency and fuel efficiency. The timing chain uses a chain, a DISA variable-length manifold is used at the inlet, the injectors are installed in the cylinder head, the Siemens MSV70 engine management system.
This engine was used on BMW 23i and 25i cars. The replacement for the N52B25 engine came out already 2 years after its start of production, represented by the N53B25 and strangled versions of the N53B30, however, 2.5 liters. The N52 was produced for a long time and was discontinued only in 2011.
BMW N52B25 engine modifications
- N52B25U1 (2005 - 2008 onwards) - the base engine strangled by the intake manifold, 177 hp at 5800 rpm, torque 230 Nm at 3500-5000 rpm. For versions with index 23i.
- N52B25 (2009 - 2011 onwards) - a bloated 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.
BMW N52B25 engine problems and malfunctions
- The biggest problem with 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 (KVKG). The problem was solved on motors from 2007, called N52NB25 (black cover).
- If you spit on high oil consumption and continue driving as it is, then a little later the catalysts begin to clog. Exit: A. Buy new catalysts, it's expensive. B. Buy flame arresters, it's cheap.
- Ticking sound. It manifests itself in cold weather and is a feature of engines manufactured before 2009. There are no negative consequences for the motor from this.
- The turns are floating. Such problems are usually associated with Valvetronic, flow meter or Vanos valves. On N52, vanos often causes problems due to improper maintenance (oil change every 20 thousand km, use of low-quality oil). Repairing vanos is simple: first flush the vanos valves, if the problem persists, then replace. Check it out. 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 too durable electronic pump, which requires replacement every ~ 80-100 thousand km, To reduce the likelihood of various troubles, oil in the N52 engine it is recommended to pour a high-quality one, recommended by the manufacturer, it is also not worth saving on gasoline, as the auto technical center is engaged in changing the oil in the BMW engine.
Characteristics of the N52B25 engine
| Production | Munich plant |
| Engine brand | N52 |
| Years of release | 2005-2011 |
| Cylinder block material | magnesium-aluminum |
| Supply system | injector |
| A type | inline |
| Number of cylinders | 6 |
| Valves per cylinder | 4 |
| Piston stroke, mm | 78.8 |
| Cylinder diameter, mm | 82 |
| Compression ratio | 11 |
| Engine displacement, cubic cm | 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 standards | 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, gr. / 1000 km | up to 1000 |
| Engine oil | 5W-30 5W-40 |
| How much oil is in the engine, l | 6.5 |
| When replacing pouring, l | ~6.0 |
| Oil change is carried out, km | 10000 |
| Engine operating temperature, deg. | ~95 |
| Engine resource, thousand km - according to the plant - on practice |
- |
| Tuning, hp - potential - without loss of resource |
280+ n.d. |
| 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 |
