Positive Crankcase Ventilation Valve: Testing and Inspection

Positive Crankcase Ventilation Valve:

PROCEDURE
If an engine is idling rough, check for a clogged PCV valve or plugged hose. Replace as required. Use the following procedure:

1. Remove PCV valve from 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 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 the needle inside the valve. If valve does not rattle, replace valve.

NOTES ON OPERATION
With this system, any blowby in excess of the system capacity (from a badly worn engine, sustained heavy load, etc.) is exhausted into the air cleaner and is drawn into the engine.

Proper operation of the PCV system is dependent upon a sealed engine. If build up of oil sludge or dilution is noted, and the PCV system is functioning properly, check engine for possible cause and correct to ensure that the system will function as intended.