Crankcase ventilation system (Mercedes-Benz E-Class W124)

The engine crankcase ventilation system consists of hoses of a fairly large cross-section connecting the engine crankcase with the cylinder head cover, and the air supply system to the engine, a pressure control valve and an oil separator.

The engine crankcase ventilation system is a forced closed type. The ventilation ensures the suction of crankcase gases and fuel vapors from the crankcase into the engine intake manifold, which eliminates the increase in pressure in the crankcase due to the penetration of exhaust gases into it and their release into the atmosphere.

Servicing the crankcase ventilation system components mainly involves checking the hoses for patency and, if necessary, cleaning them.

(Text republished from the website MercedesMan)