The first M40 engine rolled off the assembly line in 1987, and production of the motor continued until 1995. From its predecessor, he inherited a cast iron cylinder block (cast from gray cast iron). It is possible to bore cylinders for overhaul dimensions. Eight counterweights balance the operation of the solid crankshaft. The drive of the gas distribution mechanism has become a belt, and the adjustment of thermal clearances is carried out by oil hydraulic compensators. The M40B16 engine has a displacement of 1596 cc. It was produced with a power of 100 and 102 hp. The Motronic injection system in 1991 for the E36 body was changed to a newer one. The cylinder diameter is 84 mm and the piston stroke is 72 mm.
|Cylinder block alloy||cast iron|
|Number of cylinders||4|
|Valves per cylinder||2|
|Piston stroke, mm||72|
|Cylinder bore, mm||84|
|Power output, hp||100/5500
|Torque output, Nm / rpm||141/4250
|Fuel consumption, L/100 km
|Oil consumption, gr/1000 km||up to 1000|
|Recommended engine oil||0W-30 / 0W-40 / 5W-30 / 5W-40 / 10W-40 / 15W-50|
|Engine oil capacity, liter||4.0|
|Amount of engine oil for replacement, liter||~7.0|
|Oil change interval, km||7000-10000|
|Normal engine operating temperature, °C||90-95||Engine lifespan, km
— official information
Even the reliable BMW M40B16 engines are prone to breakdowns and malfunctions during long periods of operation. Due to wear on the camshaft, hydraulic compressors and rocker arms, the engine knocks.
If you notice that the rpm is floating, it is worth checking the air duct on the mass air flow sensor. The reason is often air leakage, violation of the integrity of the element. Next, the condition of the valve, throttle valve, lambda probe is diagnosed. The problem may be related to KXX. Floating rpm is caused by poor camshaft rotation.
If there are dips during acceleration, check the injectors, which are usually sufficient to clean. If the motor overheats, you need to check the condition of the pump, radiator. You should also inspect the thermostat. Problems arise when there are air locks in the cooling system, look at the condition of the tube.
When the car won’t start, inspect the plugs, wires, coil, and fuel pump. The reason may be trivial – the timing belt.