Positive Crankcase Ventilation: Description and Operation

PURPOSE
The Positive Crankcase Ventilation (PCV) System is used to reduce Hydrocarbons (HC) emissions by directing crankcase "blow-by" back into the intake manifold for combustion.

OPERATION






The PCV System contains a spring loaded PCV Valve that controls the amount of blow-by vapors reintroduced into the intake manifold. The valve passage size varies with intake manifold vacuum and crankcase pressure. The metered amount of blow-by vapors flows from the crankcase into the intake manifold through a connecting hose. Fresh air is introduced to the crankcase from the air intake also through a connecting hose.