PCV Valve Quick Check

1. Replace existing PCV valve with a known good one.
2. Start engine and compare existing engine idle quality with prior idle quality.
3. If loping or rough idle condition remains when the PCV valve is replaced, the PCV system is not at fault. Further engine component diagnosis must be made to determine cause of malfunction.
4. If idle quality improves, replace PCV valve and clean hoses and fittings.