Positive Crankcase Ventilation: Testing and Inspection

Checking PCV Valve:

1. Warm engine to operating temperature and run at idle.
2. Disconnect PCV valve and ventilation hose from cylinder head cover.
3. Place a finger over valve opening. Check that vacuum is felt.
4. Remove valve and blow through from both directions. Verify that air flows through valve in one direction only (toward the intake manifold).
5. Replace valve if necessary.