Engine Oil System

ENGINE OIL SYSTEM




The oil supply system of the S62B50 engine is specifically designed for the M5, due to its ability for high speed cornering (transverse acceleration of up to 1.2 g) that could cause the engine oil to be forced (and trapped) into the outer edge of the cylinder head and the rear area of the oil sump. To prevent oil starvation from occurring during these driving situations, two additional scavenging oil pumps are installed within the main oil pump housing. The main oil pump's function is to supply the engine with the required volume of oil for all of its lubrication needs. The two additional pumps only supply the oil sump with the scavenged oil.




Each additional oil pump incorporates a solenoid changeover valve that is connected to two scavenging tubes that are connected to the rear section of the oil pan and the outer edge of the cylinder head. The scavenging tubes in the oil pan crossover so that the right side pump draws from the rear left side of the pan and the left pump from the right side of the pan.

OIL PUMP OPERATION




While driving straight ahead, the two oil pumps draw oil from the rear of the oil pan to supply the main oil pump pick up.




When cornering at forces > 0.9 g, one solenoid will be switched on to draw oil from the cylinder head while the second solenoid will continue to draw oil from the rear of the pan. The engine control module receives the G-force signal from the DSC control module over the can line.

OIL COOLING




The S62 engine is equipped with an oil-to-coolant heat exchanger. It is mounted in the "V" of the block and serves to heat the oil during engine warm up and cool the oil during normal driving. Oil and coolant and passageways are cast into the block and formed "O" rings are used to seal the the heat exchanger. The coolant return is through external lines back to the thermostat housing.

A differential pressure control valve is integrated into the heat exchanger on the oil side. The valve opens an oil bypass in the event that the exchanger should become clogged. or at very low start temperatures. This ensures that the engine will receive sufficient lubrication under all driving conditions.