Positive Crankcase Ventilation: Testing and Inspection

Crankcase Ventilation System Inspection/Diagnosis

Inspection Procedure

1. Inspect the positive crankcase ventilation (PCV) valve, the PCV hoses, and all connections for leaks or restrictions. Repair as necessary.
2. Start the engine.
3. At idle, listen to the PCV valve while lightly pinching the PCV hose with your fingers or pliers. Perform this test several times. Each time the hose is pinched, the valve should make an audible click.
4. If there is no click, inspect the PCV valve grommet for cracks or damage.
5. Blow air into the PCV valve. The air should pass through the PCV valve with high resistances.
6. If the grommet is OK, replace the PCV valve.