Positive Crankcase Ventilation: Testing and Inspection

This test is to see if PCV System is functioning properly.


1. Check for correct PCV valve and properly mounted PCV Valve in rubber grommet, make sure hoses & clamps are tight and in place.
2. Start engine and let idle.
3. Remove PCV valve from valve cover and place thumb over valve.
4. RPM should drop & vacuum should be felt.
5. If no vacuum is felt check for a clogged PCV. valve, hose, or intake manifold port.
6. Turn the engine off & remove the PCV. valve from hose. Shake the PCV. valve & listen for rattle. If no rattle is heard replace the valve.