Q: How Does the Positive Crankcase Ventilation (PCV) System and PCV Valve Work on Dodge Grand Caravan?
A: The Positive Crankcase Ventilation (PCV) system reduces hydrocarbon emissions by scavenging vapors from the crankcase. It consists of a PCV valve, a fresh air filtered inlet, and vacuum hoses. To maintain idle quality, the PCV valve restricts the flow when the intake manifold vacuum is high. To check the valve's operation, with the engine running at idle, pull the valve out and place your finger over the valve inlet. A strong vacuum should be felt and a hissing noise should be heard if the valve is operating properly. Cleaning the old valve is not recommended.