PCV Valve

PCV Valve:

In order to maintain idle quality, the PCV valve restricts the flow of blowby gas whenever intake manifold vacuum is high. Abnormally high crankcase pressure may cause the blowby gases to flow through the crankcase vent tube and into the air cleaner. The blowby gases are then drawn into the intake system and consumed in the normal combustion process. The relationship between the flow of blowby gas and engine manifold vacuum is charted in the table:

PCV Valve Operation:

RESULTS OF INCORRECT OPERATION
A plugged valve or hose may cause any of the following conditions:
^ A rough engine idle
^ Engine stalling or low engine idle speed
^ High engine crankcase pressure
^ Engine oil leaks
^ Engine oil in the air cleaner
^ Oil sludge in the engine
^ Engine oil consumption
^ Excessive exhaust emissions

A leaking valve or hose may cause any of the following conditions:
^ A rough engine idle
^ Engine stalling
^ High engine idle speed
^ Incorrect engine crankcase pressure
^ Excessive exhaust emissions