Operation CHARM: Car repair manuals for everyone.

Positive Crankcase Ventilation Valve: Service and Repair




PCV Valve Inspection

1) Disconnect PCV valve from cylinder head cover and install plug in head cover hole.
2) Run engine at idle.
3) Place your finger over end of PCV valve (1) to check for vacuum.

If there is no vacuum, check for clogged valve. Replace PCV valve as necessary.





4) Stop engine and remove PCV valve (1).

Install clean hose to valve and check that there is air flow when blowing breath into hose from [a] to [b] and that there is no air flow when blowing breath into hose from [b] to [a] as shown in figure.

If faulty condition is found, replace PCV valve.