Positive Crankcase Ventilation: Testing and Inspection

Crankcase Ventilation System Inspection/Diagnosis (LCV)

Special Tools

EN 23951 - Valve Manometer

For equivalent regional tools, refer to Special Tools Special Tools.

1. Verify clean air cleaner.

2. Verify oil fill cap is in place.

3. Verify oil level indicator is installed.

4. Remove the oil level indicator. Install a EN 23951 - valve manometer or equivalent into the oil level indicator hole.

5. Start the engine.

6. Check for slight vacuum. The vacuum level should be less than 3.377 kPa (1 in Hg).

7. If vacuum is higher, inspect and verify that the clean air hose from cam cover to air intake is not blocked or kinked.

8. If vacuum is in the normal range, remove PCV line from fresh air valve near the oil fill cap. Block the fresh air valve and also plug the fresh air hose. Vacuum should increase on the manometer. If held too long, vacuum will be drawn through the crankshaft seals creating a sucking sound.

9. If vacuum does not increase, the orifice between the camshaft cover assembly and the cylinder head assembly could be plugged.

10. If there is zero vacuum or pressure, verify compression of the engine.

11. If compression is normal, check for a blocked orifice between the camshaft cover assembly and the cylinder head assembly. Clean the orifice.