Engine BMW M42B18 under the hood

Engine BMW M42B18

The M42 B18 is a 1796cc water-cooled gasoline engine. and a power of 136 hp. Fuel injection system – Bosch Montronic M1.7. The catalytic converter engine versions developed a power of 100 kW and a torque of 170 Nm and met Euro 2 standards.


Manufacturer Munich Plant
Also called M42
Production years 1989-1996
Cylinder block alloy cast iron
Fuel system injector
Configuration inline
Number of cylinders 4
Valves per cylinder 4
Piston stroke, mm 81
Cylinder bore, mm 84
Compression ratio 10
Displacement, cc 1796
Power output, hp 140/6000
Torque output, Nm / rpm 175/4500
Fuel type 95
Euro standards Euro 2
Weight, kg
Fuel consumption, L/100 km
— city
— highway
— combined
Oil consumption, gr/1000 km up to 1000
Recommended engine oil 0W-30 / 0W-40 / 5W-30 / 5W-40 / 10W-40
Engine oil capacity, liter 5.0
Oil change interval, km 7000-10000
Normal engine operating temperature, °C 90-95
Engine lifespan, km
— official information
— real


Frequent problems

Engine BMW M42B18
Among the problems typical for the M42B18: unstable rpm, knocking, jolts during acceleration, overheating.

A knock in the power unit appears due to wear on the camshaft, hydraulic lifters and rocker arms. Verification required.

If the revolutions are unstable, the reason may be hidden in the violation of the integrity of the duct, air leaks are possible. They also inspect the lambda probe, DMRV, KXX and the throttle valve. If the camshaft is difficult to rotate, this causes a floating speed problem.

The engine begins to overheat when the pump, radiator, thermostat breaks down. Air pockets in the cooling system may be the cause. You also need to check the integrity of the plastic pipes in the cooling system.

When the engine jerks during acceleration, it is most likely that the injectors need to be cleaned. If the engine does not start, check the spark plugs, the fuel pump, the ignition coil, and high-voltage wires.

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