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



ECCS system Refer to On Board Diagnostics malfunction. in "Testing Procedures" in Emissions
to extract trouble codes.



EGR inoperative. Check EGR system in "Testing
Procedures" in Emissions.



Ignition timing advanced. Check ignition timing in "Adjustment
Procedures" in Emissions.



Air diverter door binding or Check automatic temperature control system
air cleaner temperature in "Testing Procedures" in Emissions.
sensor malfunction.



Poor or contaminated fuel. Recommend higher grade fuel.