Crankcase Ventilation Systems: Description

NOTE: Diesel Pickup models do not use a PCV system.

The crankcase ventilation system is designed to return blow-by gases to the engine, through the intake manifold and air cleaner. Gasoline models use a PCV valve to control blow-by flow, while diesel models have a crankcase emission control valve to perform the same function.

Fig 1: Datsun Crankcase Ventilation System (Fuel Injected Models)

Courtesy of NISSAN NORTH AMERICA, INC.