Positive Crankcase Ventilation: Testing and Inspection

Crankcase Ventilation System Inspection/Diagnosis

Inspection Procedure





Caution: Do not breathe the air through the EVAP component tubes or hoses. The fuel vapors inside the EVAP components may cause personal injury.

1. Inspect the positive crankcase ventilation (PCV) valve (3), the hoses (1, 2), and all connections for leaks or restrictions. Repair as necessary.
2. Start the engine.




3. At idle, listen to the PCV valve (2) with a mechanics stethoscope (1) while lightly pinching the PCV hose (3) 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. If the grommet is OK, replace the PCV valve.