Positive Crankcase Ventilation Valve Check
- Hold the positive crankcase ventilation (PCV) valve with the vacuum side down. Insert a thin rod, and using light pressure, depress the end of the PCV valve spring by 5 - 10 mm (0.2 - 0.3 inch). Release pressure on the rod to see if the PCV valve spring will lift the rod to its original position.
- If the rod returns quickly to its original position, the PCV valve is OK. If the stick does not return quickly, clean or replace the PCV valve.
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.