Positive Crankcase Ventilation: Description and Operation

The PCV system, consists of a PCV valve mounted on the intake manifold connected to a hose that is fed into a hose connecting the air cleaner to the valve cover. During small throttle opening/high vacuum conditions, crankcase gasses flow from the valve cover through the PCV valve. During large throttle openings/low vacuum conditions, crankcase gasses flow from the valve cover to the air cleaner.