M52B20 engine - unit characteristics from BMW!

The M52B20 engine has not left production shops since 2000. It was replaced by the M54 model. The senior unit was developed in three modifications. Over the years of sale, the motor has also undergone several upgrades. We present you the key news about this drive!

M52B20 engine - technical data

The plant from which the M52B20 engines came out was the Bavarian Plant Group plant, owned by BMW, operating since 1992 and located in Munich. As mentioned earlier, the power unit was produced from 1994 to 2000. 

The M52B20 is an inline six-cylinder gasoline engine with four valves per cylinder in the DOHC system. At the same time, the piston diameter is 80 mm, and its stroke is 66 mm. In turn, the total working volume is 1991 cc.

This 2.0-liter naturally aspirated four-stroke engine has an 11:1 compression ratio and develops 148 hp. To use it, use 0W-30, 0W-40, 5W-30 or 5W-40 oil and change it every 10-12 km. km or every 6.5 months. The substance tank has a capacity of XNUMX liters.

Models of cars on which the engine was installed

The M52B20 engine powered the E36 third series as well as the E39 fifth series. BMW engineers have also used this assembly in E46 vehicles since the late 90s, and the engine also appeared in the E38 7 Series and E36/E37 Z3.

Drive design

The 52-liter inline six-cylinder engine belongs to the MX series. For this reason, there are many similarities in design between this model and the M52B24, M52B25, M52B28 and S52B32 variants. The M52B20 block replaced the M50B20 model.

BMW designers decided to use an aluminum cylinder block. This material was also used to make the 32-valve DOHC head. Compared to the M50B20 variant, brand new pistons and 145 mm long connecting rods are also used. 

The engine equipment also includes a variable valve timing system VANOS only on the intake camshaft, as well as a simple intake manifold, which is made of plastic. The engine also has 154cc fuel injectors.

How to improve the wear resistance of cylinder liners?

In the case of the M52B20, an additional layer of Nikasil was applied to the cylinder liners. The coating consists precisely of an electrophoretically lipophilic layer of nickel and silicon carbide. Its use resulted in greater durability of the components to which it was applied, comparable to cast iron or chromium components.

New solutions in 1998 - how was the design of the bike developed?

Four years after the powertrain went on sale, BMW decided to take further steps to improve the design. Cast iron liners were added to the aluminum cylinder block. In addition, the connecting rods, pistons and cooling system have been completely rebuilt.

Also added were a Double-VANOS system, a DISA variable geometry intake manifold and an electronic throttle body. Valve lift was 9,0 / 9,0 mm, and the updated power unit was called the M52TUB20. In 2000, it was replaced by a model from the M54 series - the M2,2B54 unit with a volume of 22 liters.

Operation and most common problems

Common malfunctions are radiator and expansion tank leaks. Users of cars with the M52B20 also complain about a rather emergency water pump and uneven idling, which is usually caused by a faulty control valve. There are also valve cover problems and oil leaks, as well as broken double relief valves.

What to look for when choosing an M52B20 engine?

It's worth noting here that the M52B20 engines are fairly old units - the last one is over 20 years old. For this reason, probably, each of them has a high mileage. The key point at such a time is a thorough detailed inspection and identification of the most worn parts. 

The most important thing is the good condition of the engine support system. This is a cooling system with a water pump, radiator and expansion tank. These components are the most susceptible to failure. Therefore, before buying a bike, you need to check their serviceability.

On the other hand, internal components such as valves, chain, connecting rods, cranks and seals can work without problems even with more than 200 km of driving. km. By allocating a certain budget for initial repairs and bringing the unit to optimal technical condition, the BMW M52B20 engine will pay you back with good work - despite its age.