Positive Crankcase Ventilation: Testing and Inspection

Crankcase Ventilation System Inspection/Diagnosis

1. Remove the positive crankcase ventilation (PCV) valve. Refer to Positive Crankcase Ventilation Valve Replacement (Service and Repair).




Warning: Refer to Fuel Vapors in Evaporative Emission Components Warning (Service Precautions).

2. Blow air into the cylinder head side of the PCV valve.
3. Check that air passes through the PCV valve easily.




4. Blow air into the intake manifold side of the PCV valve.
5. Check that air passes through the PCV valve with high resistances.
6. If the PCV valve fails either test, replace the PCV valve. Refer to Positive Crankcase Ventilation Valve Replacement (Service and Repair).
7. Inspect the PCV hose for damage, restrictions, or leaks. Replace the hose as necessary.
8. Inspect all PCV system passages and connections for leaks or restrictions. Repair as necessary.