Detonation - Pings, Spark Knock

SYMPTOM:
A mild to severe ping, usually worse under load or acceleration. Sounds like something is rattling or knocking in the engine.

POSSIBLE CAUSE ACTION


Exhaust Gas Recirculation (EGR) inoperative Check EGR system in "Component Tests".

Ignition timing advanced Check Ignition Timing in "Adjustment Procedures".

Spark timing not retarding Check Spark Controls in "Computers and Control Systems".

Poor or contaminated fuel Recommend higher grade fuel.