Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the logical successor to CHARM, I recommend you try it!

Link: lemon-manuals.la

Functional Check

If engine is idling rough, check for a clogged PCV valve or hose. Check the PCV valve identification number to be sure the correct valve is installed Replace as required.

Use the following procedure to determine if the PCV valve is functioning properly:
1. Remove PCV valve from cam cover grommet.
2. Run engine at idle.
3. Place your thumb over end of PCV valve to check for strong vacuum signal. If there is no vacuum present, check for clogged hose, plugged valve or plugged intake manifold port. Replace any clogged components or clean out plugged port.
4. Turn off engine and remove PCV valve from hose. Shake valve and listen for the plugger to rattle inside the valve. If valve does not rattle, replace valve.