Rough Idle
- Check for burned or sticking valves.
- Check for incorrect valve clearance.
- Check for blown head gasket.
- Check for burned valve seats.
- Check for faulty ignition system.
- Check for faulty fuel system.
- Check for an intake air leak. Idle speed will usually be faster if an intake air leak is present.
- Check for air leaking into or out of the exhaust system.