BMW N52B25OL engine

N52B25OL is a gasoline power unit with a maximum output of 218 horsepower and a displacement of 2.5 liters. This engine can be found under the hood of the BMW 5 Series.

Engine specifications N52B25OL

Advantages

This is another engine with a displacement of 2.5 liters, which belongs to the new line of N52 (this line also includes the N52B30 engine), is characterized by an in-line layout and six cylinders. The first appearance of the power unit was recorded in 2005, to replace the then popular M54B25 engine. Unlike past generations of the M engine family, this powertrain is all-new. The engine is based on an even lighter cylinder block made of magnesium-aluminum alloy. It also features a new lightweight cylinder block and a modified crankshaft.

The N52B25 engine design uses an updated cylinder head, which is equipped with the well-known to all system of variable valve timing, located on two camshafts Double-VANOS. In addition, the system is accompanied by the Valvetronic variable valve lift system. All this allowed to increase the output of the engine, as well as to ensure lower fuel consumption. The timing system uses a chain. The DISA intake manifold is variable in length. The fuel injectors are mounted in the cylinder head.

The Bavarians rolled out a replacement for the N52B25 powertrain 2 years after they started producing it. The motor was replaced by the N52B25 version, as well as the strangled N53B30 engine, but the N52B25 was produced for a few more years, and was completely discontinued only in 2011.

Disadvantages

The most common problem with the N52B25OL engine is increased consumption of lubricating fluid. The reason for this malfunction is the use of thin oil rings, which lose their properties very quickly. Worn oil caps can also cause a lot of problems. A distinctive feature is that such problems can occur at mileages up to 100 thousand kilometers. It is necessary to check the condition of the nodes and, if necessary, replace them with new rings with caps. At the same time you can check the condition of the crankcase ventilation valve. Motors that were produced after 2007 do not suffer from this problem, a distinctive feature of such engines is the installation of a black cap.

You can ignore the increased consumption of lubricating fluid and just keep driving as is. But this leads to the fact that after a certain mileage the catalytic converters start to clog. There are several ways out: buying new expensive catalytic converters, or buying cheap flame arresters.

A ticking sound may occur when the engine is running. As a rule, this problem is observed only on motors manufactured before 2009 and occurs during cold running. There are no negative consequences for the power unit.

Owners of cars with such a motor under the hood may encounter the problem of floating revolutions. As a rule, such malfunctions are caused by the failure of the Valvetronic system, the Vanos valve or a broken flow meter. The vanos system quite often causes problems for owners of such motors, due to improper maintenance. Oil should be changed more often than once every 20 thousand kilometers, and try to use only quality lubricant. Repair the Vanos system is relatively simple: first you need to wash the valves of the system, and if the problem does not go away, then you have to replace the unit completely.

In addition to the fact that the power unit is very prone to overheating, it is necessary to constantly check the condition of the cooling system and keep the radiator clean. The design of the power unit uses a water pump, which does not have a great resource, and is not able to pass more than 100 thousand kilometers. In order to maximize the need for major repairs, you should use only high quality lubricant recommended by manufacturers and do not save on fuel.

Modifications

The N52B25U1 is a strangled base version of the powertrain that has been strangled with an intake manifold. The maximum output of this motor is 177 horsepower and peak torque has reached 230 Nm.

N52B25 is a blown modification of the motor, which was produced from 2009 to 2011. The engine design used a different intake manifold. Maximum power was 204 horsepower, and peak torque reached 250 Nm.

Technical specifications

The exact displacement of the inline six-cylinder power unit is 2,497 cubic centimeters. The diameter of the cylinders is 82 millimeters. There are four valves per cylinder. A crankshaft with a piston stroke of 78.8 millimeters gives a compression ratio of 10.7 to 1.

During engine operation, up to 178 grams of harmful substances are emitted per kilometer traveled. The average fuel consumption of the N52B25OL is about 10 liters per 100 kilometers.

Maximum power of 218 horsepower is achieved when the engine is revved up to 6.5 thousand rpm. Peak torque of 250 Nm is developed at 2,750 rpm.

Tuning

This power unit is not characterized by a special adaptation to refinements aimed at increasing its performance, so the best choice is to buy a car with more power. But if you really want to, you can try to make a classic chip tuning. Purchasing a sport exhaust system along with an air filter, as well as installing new software can add about 20 more horsepower.

You can try to increase the power of the N52B25OL with the help of a compressor. Those car owners who don’t have enough of this power boost can try to build a compressor version of the engine. You will have to buy a kit from ARMA, which will give you the opportunity to raise the maximum power to 300 horsepower on a standard piston.

This engine is installed on the following models:

BMW 5-Series (E60)