Positive Crankcase Ventilation: Testing and Inspection

Fig 3 PCV Valve:

WARNING: Apply parking brake and/or block wheels before performing any test or adjustment with the engine operating.

1. With engine idling, remove the hose from the PCV valve.
- If the valve is not plugged, a hissing noise will be heard as air passes through the valve.
- A strong vacuum should also be felt when a finger is placed over the valve inlet.
2. Install hose on PCV valve.
- Remove the make-up air hose from the air plenum at the rear of the engine.
- Hold a piece of stiff paper (parts tag) loosely over the end of the make-up air hose.
3. After allowing approximately one minute for crankcase pressure to reduce, the paper should draw up against the hose with noticeable force.
- If the engine does not draw the paper against the grommet after installing a new valve, replace the PCV valve hose.
4. Turn the engine off.
- Remove the PCV valve from intake manifold.
- The valve should rattle when shaken.
5. Replace the PCV valve and retest the system if it does not operate as described in the preceding tests.
- Do not attempt to clean the old PCV valve.
- If the valve rattles, apply a light coating of Loctite Pipe Sealant With Teflon to the threads.
- Thread the PCV valve into the manifold plenum.
- Tighten to 7 Nm (60 in. lbs.) torque.