Positive Crankcase Ventilation: Description and Operation

PCV System:

DESCRIPTION
Crankcase vapors and piston blow-by are removed from the engine by manifold vacuum. These emissions pass through the PCV valve into the intake manifold where they become part of the calibrated air-fuel mixture, are burned and expelled with the exhaust gases. When there is not enough vapors or blow-by present in the engine, make up air is drawn from the air cleaner. No fresh air enters the crankcase with this system.