Detonation - Pings, Spark Knock

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 Check the EGR system under
TESTING PROCEDURES.


Ignition timing advanced Check Ignition Timing. Refer to
ADJUSTMENT PROCEDURES.


Spark timing not retarding Check Spark Controls. Refer to
COMPUTERIZED ENGINE CONTROLS.



Poor or contaminated fuel Recommend higher grade fuel