Positive Crankcase Ventilation Valve: Description and Operation

PURPOSE
The Positive Crankcase Ventilation (PCV) Valve is used to meter the amount of blow-by vapors that flow from the crankcase to the intake manifold.

OPERATION
The PCV Valve contains a spring loaded check valve that allows the amount of blow-by vapors reintroduced into the intake manifold to be controlled. The valve passage size is dependent upon intake manifold vacuum and crankcase pressure.