Detonation -- Pings & Spark Knocks

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

POSSIBLE CAUSE ACTION


EGR inoperative See Exhaust Gas Recirculation


Ignition timing advanced Check Ignition Timing.
See Adjustments


Spark timing not retarding Check Spark Controls.
See Computers and Control Systems



Poor or contaminated fuel Recommend higher grade fuel