Positive Crankcase Ventilation: Testing and Inspection

DIAGNOSIS AND TESTING

1. If troubleshooting high crankcase pressure, the following items can be causing the closed crankcase ventilation valve to close during engine operation:
- A restricted crankcase ventilation filter. Change the filter
- A malfunctioning or incorrectly assembled closed crankcase ventilation valve. Check the valve operation.

2. The closed crankcase ventilation valve should allow crankcases gases to flow when the engine is not running and/or removed from the engine.

NOTE: Application of air can be applied either to the inlet or outlet of the closed crankcase ventilation valve.

3. A small amount of air can be blown through the closed crankcase ventilation valve (less than 34 kPa [5 psi]) to check the closed crankcase ventilation valve.
4. If air does not go through the closed crankcase ventilation valve, replace the valve.