Positive Crankcase Ventilation: Testing and Inspection

PCV Valve:

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

TEST DESCRIPTION:

1. Check for a correct PCV valve, and a properly mounted PCV Valve into the rubber groument. Make sure the hose(s) and clamp(s) are tight, and in place.
2. The engine should be at normal operating temperature.
3. Start the engine, and let idle.
4. Remove PCV valve from valve cover, and place thumb over valve.
5. Engine rpm should drop, and vacuum should be felt.
6. If no vacuum is present, check for a clogged PCV valve, hose, or intake manifold port.
7. Remove engine oil dipstick, and install a vacuum gauge over the dipstick tube.
8. Run engine at 1500 rpm for 30 seconds. Read the vacuum gauge at 1500 rpm.
9. If vacuum is present, the PCV system is functioning properly.
10. If no vacuum is present, the engine may not be sealed and/or is drawing in air from the atmosphere. Check the valve covers, oil pan gasket, etc... for air leaks.
11. If the vacuum gauge registers a pressure or the vacuum gauge is pushed out of the tube, check for correct PCV valve, plugged hose, or excessive engine blow-by.
12. Turn the engine off, and remove the PCV valve from the hose. Shake the PCV valve and listen for a rattle. If a rattle is not heard, replace the PCV valve.