Detonation/Spark Knock/Pings

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 malfunction To check EGR proceed to
EXHAUST GAS RECIRCULATION SYSTEM..

Ignition timing advanced To check ignition timing proceed to
ADJUSTMENT PROCEDURES.

Incorrect Spark Advance Refer to
COMPUTERIZED ENGINE CONTROLS.

Poor or contaminated fuel Recommend higher grade fuel.