The appearance of this model will be relevant for more than one year, and its body is able to survive many, and even younger classmates. In this article, we will try to touch on the most important points that you should pay attention to when purchasing a BMW 3 Series in the back of the E90. We will not describe the driving performance of this “troika” - those who chose this particular car know better about them than others, so we will immediately turn to the technical part.
Choosing a pre-styling option in which the native head optics have been preserved, one should be prepared to replace it. As practice has shown, plastic headlights E90 prone to cracking. For new original headlights, you will have to pay a tidy sum (about 900 euros for 1 pc.), But if you choose an analog, you can meet half the cost of the original.
When operating a car in winter conditions, when the road surface is treated with a sand-salt mixture and salt brines, an electrician suffers in the BMW e90. In dorestyling versions in the risk zone, the terminal of the plus wire of the JunctionBox fuse box, which often completely rots in a few years. In this case, the replacement of the entire unit will be required, and this is an additional cost in the range of 300-400 euros. Another mechanism that suffers from corrosion is the wiper drive, because of which the motor can fail, the load on which increases several times. The same goes for the folding mechanism of automatic mirrors.
The next common “disease” is the stove motor, or rather, its bearings, which begin to “whistle”, and when purchasing cars with dual-zone climate control, you need to be prepared to replace the heater valves and an additional pump (250 and 150 euros, respectively).
Damage to seat heating on the BMW e90 is not so common, and the heating elements themselves are not expensive (about 40 euros). On versions with sports seats, such a breakdown “will cost a pretty penny” due to the fact that in this case the heating elements change only together with the upholstery (from 400 to 800 euros, depending on the type of material).
As for the electrics of gasoline engines, it is quite reliable. An exception is motors with a Valvetronic throttle-free system, in which the servo-drive of the eccentric shaft, which regulates the opening of the intake valves, is often “buggy”. As practice has shown, its service life does not exceed 60 thousand km. Ignition coils can be equated to consumables, but the service life of the generators turned out to be quite high - up to 300 thousand km without replacing the elements. However, depending on the operating and maintenance conditions, it is often necessary to complete a complete overhaul of the motor for such a run. It is worth noting that in the vast majority of cars on the market are offered cars with twisted mileage, so the odometer should not be trusted. Understand what condition the car can only be diagnosed. For example, you can learn about its real mileage by reading information from different blocks (light control unit, ABS unit, etc.), where if errors occur, the current mileage will be recorded, which most often will not coincide with the declared mileage. In addition, when twisting the path, the “masters” often forget about the additional key, which can preserve the original mileage of the car.
We should also mention the N52 and N46 engines without a mechanical oil level dipstick, which replaced the legendary M54. In an effort to reduce weight and improve efficiency, the Bavarian engineers used a bimetal alloy of aluminum and magnesium in the design of the N series engines, which negatively affected their reliability. One of the main “features” of these, even new engines is the increased oil consumption, which can reach up to 1 liter per 1 thousand km (especially on engines with a displacement of 2.5 liters). The reason is the shape of the pistons and the small thickness of the rings. The cost of replacing the cylinder-piston group on such engines will cost at least 2000 euros.
With high mileage, increased oil consumption is facilitated by “stiffened” valve seals, and in vehicles with four-cylinder N46 engines, especially the first years of production, oil leakage from under the valve cover gasket can occur at intervals of 50-60 thousand km.
The crankcase ventilation system should be checked with the same frequency, the weaknesses of which are the oil separator membrane and deposits in plastic pipelines.
Separate attention to themselves requires a cooling system. The fact is that there is no coolant temperature gauge on the dashboard. As you know, overheating, especially for six-cylinder engines, is very dangerous. Therefore, it is necessary to regularly check the external cleanliness of the radiator cells and change the cap of the expansion tank with a frequency of 60-70 thousand km, the valve of which is prone to jamming, which in turn will cause the occurrence of excessive pressure with the breakdown of the pump and thermostat.
On gasoline engines, the timing chain “nurses” more than 200 thousand km without replacement, but on the N47 2.0-liter diesel units it is considered the “weak link”. On this unit, chain weakening can reach such a critical level that it will jump to several teeth or break at all. This is due to the unsuccessful design of the damper and tensioner.
As for the BMW e90 transmission, this is a fairly reliable unit that does not require special attention, of course, subject to timely service. Versions with the xDrive all-wheel drive system and Getrag manual gearboxes performed particularly well. Versions with six-band “automatic machines” ZF series 6HP with a mileage of more than 250 thousand km can cause smudges of oil through gaskets and seals (replacement of about 300 euros), and with a mileage of more than 350 thousand km, it may require a complete overhaul with the replacement of friction clutches, torque converter and electronic-hydraulic unit (from 2000 to 3000 euros).
The “survivability” of the BMW e90 suspension in our conditions is enough for 40-50 thousand km. Most often, stabilizer struts, shock absorbers, as well as levers (especially the front ones) fall under the replacement. The steering rack and power steering "nursed" up to 200 thousand km, the main thing is not to miss the beginning of the characteristic hum of a worn-out unit in order to avoid getting metal shavings into the system.
Compared to the BMW e46, the trio in the body of the e90 has become less reliable, especially versions with six-cylinder gasoline engines and a diesel engine with an N47 unit. We would recommend choosing restyled modifications with 3.0-liter gasoline engines and “old” diesel engines with cast-iron cylinder blocks.