Detonation/Spark Knock

If engine exhibits a mild-to-severe ping or knock (usually worse under acceleration), check the following:

• Verify base timing is correct.
• Check for contaminated or poor quality fuel.
• Check Electronic Spark Advance (ESA) system.
• Check EGR system operation.
• Ensure spark plug application and gap is correct.
• Check engine oil level.
• Check for obvious engine overheating.
• Check for correct operation of thermostatic air-cleaner assembly.
• Check for vacuum leaks.
• Check air induction for leaks.
• Check for incorrect basic engine parts such as camshaft, cylinder heads, pistons, or broken balancer or pulley.
• Ensure PROM application is correct. Check with dealer for latest application information.
• Use engine cleaner to remove carbon from engine.