PCV Valve

The Positive Crankcase Ventilation valve allows air to flow from the crankcase to the intake manifold. Air will not flow in the opposite direction. The resulting negative pressure in the crankcase causes air to be pulled from the air cleaner into the engine via the oil fill cap. Normally these gases in the crankcase would be vented to the air, with this reburning of the gases, hydrocarbon emissions are reduced significantly.

Copyright © 1995, Ted Felix