The Most Common BMW M10B18 Engine Problems

The M10B18 engine was created by A. Von Falkenhausen. Baron, an engineer and race car driver, began to develop a power unit in 1958. The concern offered to design an installation with a volume of 1.3 liters.

However, the engineer considered that such a motor would not work for a BMW. He was convinced that cars needed a setup with at least 1.5 displacement. l.

As a result, 4 years later he created an engine marked M115. It was produced (3.5 million pieces) until 1988, and its design made it possible to change the engine volume within 1.5-2 liters.

Below we will consider the M10B18 engine.

This engine is installed on the following models:

  • BMW 3 Series (E30)
  • BMW 3 Series (E21)
  • BMW 5 Series (E28)
  • BMW 5 Series (E12)

M10B18 engine specifications

Power, hp90 – 105
Fuel typePetrol
Volume, cm*31766
Maximum torque, N * m (kg * m) at rpm.109 (11) / 4500; 140 (14) / 4000; 140 (14) / 4500; 145 (15) / 3500; 145 (15) / 4500
engine’s typeInline, 4-cylinder, injector
Cylinder diameter, mm89
Number of valves per cylinder2
Maximum power, hp (kW) at rpm102 (75) / 5800; 105 (77) / 5800; 90 (66) / 5500
Compression ratio8.8 – 10
Piston stroke, mm71

M10B18 Advantages

  • The first modification of the engine was installed in 1963 on the 1800 sedan. It had 90 hp. and 143 Nm of torque.
  • After 5 years, this engine has changed the pistons and cylinder diameter.
  • Later, a 110-horsepower unit with a double carburetor and a torque of 147 Nm appeared.
  • After tuning the engine, BMW engineers installed a sports camshaft, and the valve lift became high.
  • Carburettors began to be taken from Weber. As a result, the engine power increased by 130 “horses”, and its torque – 153 Nm.

Finally, for almost 20 years (1969-1988), the M10B18 power unit was produced. The most popular installation M10B18 had not only a carburetor, but also an injector. Compression everywhere 11.

The engine was supplied to European markets with mechanical injection, and to Asian and North American markets – with electronic injection. Turbo installation is allowed.

The M10B18 carburetor was produced for 8 years (1980-88), had transient ignition and was installed on the 316/518 models.

Most Common M10B18 Engine Problems

The M10B18 engine is considered a reliable and successful unit. Otherwise, it would not have been produced for almost two decades. However, it is not without some problems:

  • When the engine overheats, cracks appear in the E30 M10B18 cylinder block. This can be judged by the emulsion that appears in the oil, and by the decrease in antifreeze in the expansion tank. Leaking into the engine crankcase, antifreeze increases the wear of parts that rub, which leads to overheating;
  • Fills candles, the engine troit and does not hold idle;
  • Premature failure of the eccentric washer with wear of the rocker cam;
  • Burnt cylinder head gasket;
  • The pump runs but the starter does not engage;
  • Increased oil consumption;
  • The starter clicks, but does not turn over.

However, the M10B18 on the BMW E30 is easy to repair and easy to maintain. For example, if the engine speed floats, or it rises when it is warm, or the engine stops in neutral gear, self-adjustment of idling is allowed.

The M10B18 is unpretentious to the quality of fuel and engine oil. At the end of the second decade of the 21st century, it is difficult to find a car with such a power unit on roads. Because it was discontinued 30 years ago.


For this reason, chip tuning installations are not recommended. Their resource is completely rolled out, and it is impossible to find a motor without cracks. Therefore, it makes no sense to chip it.

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