Operation CHARM: Car repair manuals for everyone.

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


Electronic Spark Advance faulty. Refer to Computers and
Control Systems.



Excessive ignition timing advance. Check Ignition Timing.
Incorrect distributor installed position. See Adjustments.


Poor or contaminated fuel Recommend higher quality fuel