Functional Check

If engine is idling rough, check for a clogged PCV system. Check for leaks in the PCV system. Replace as required.

Use the following procedures to determine if the PCV system is functioning properly:
1. Remove PCV vent from cam cover.
2. Run engine at idle.
3. Place your thumb over PCV valve to cheek for strong vacuum signal. If there is not vacuum present, check for clogged hose, plugged valve, or plugged intake manifold port. Replace any clogged components or clean out plugged port.