Engine crankcase and fuel tank ventilation system (BMW X5 E53)

The concentration of hydrocarbons in the engine crankcase and fuel tank can be many times higher than the concentration of hydrocarbons recorded in the exhaust gases.

The crankcase ventilation system (Fig. 5.27) of the engine directs crankcase gases into the intake manifold, from where they enter the combustion chamber for afterburning.



The fuel tank ventilation system (Fig. 5.28) directs fuel tank vapors into the adsorber, which is purged with atmospheric air, and gasoline vapors enter the intake manifold for afterburning.