2.0L Engine
- If engine is idling rough, check for a clogged PCV valve or plugged hose. Remove PCV valve from rocker cover. Run engine at idle. Place your thumb over the end of the valve to check for vacuum. If vacuum is not present, check for a plugged hose, manifold vacuum port or PCV valve.
- Turn engine off and remove PCV valve. Shake valve, if valve does not "rattle", replace valve. Replace any plugged or deteriorated hoses. Excess blow-by is exhausted into the air filter and drawn into the engine.
Courtesy of GENERAL MOTORS CORP.