Positive Crankcase Ventilation Valve: Testing and Inspection

PCV VALVE FUNCTIONAL CHECK
If an engine is idling rough, check for a clogged Positive Crankcase Ventilation ([1][2]PCV) valve or plugged hose. Replace as required using the following procedure:

1. Remove PCV valve from left side of intake manifold.
2. Run the engine at idle
3. Place your thumb over end of valve to check for vacuum. If there is no vacuum at the valve, check for plugged hoses or manifold port, or PCV valve. Replace plugged or deteriorated hoses.
4. Turn "OFF" the engine and remove PCV valve. Shake valve and listen for the rattle of check needle inside the valve. If valve does not rattle, replace valve.

OIL SLUDGING OR DILUTION
With this system, any blow-by in excess of system capacity is exhausted into the intake manifold and is drawn into the engine. Proper operation of the PCV system is dependent upon a sealed engine. If oil sludging or dilution is noted, and the PCV system is functioning properly, check engine for possible cause and correct to ensure that system will function as intended.