Positive Crankcase Ventilation: Testing and Inspection

Checking PCV Valve:

1. Warm engine to operating temperature and run at idle speed.
2. Disconnect valve, with hose attached, from cylinder head cover.
3. Block valve opening and ensure that vacuum is felt.
4. Remove valve and blow through from both directions. Verify that air flows through in one direction only (toward intake manifold).
5. Replace valve if necessary.