Detonation/Spark Knock

SYMPTOM DESCRIPTION:

A mild or severe ping, usually worse under acceleration. The engine makes a sharp metallic knock as engine rpm varies.


POSSIBLE CAUSE ACTION



COOLING SYSTEM MALFUNCTION Check for obvious over heating problems, low engine coolant level and leaks, water pump operation, loose belts, Faulty or incorrect thermostat, restricted air flow to radiator or restricted coolant flow, incorrect coolant solution (should be 50/50), proper fan operation (electric or belt driven).



FUEL SYSTEM MALFUNCTION Check for lean Air-Fuel mixture, O2 Sensor, perform injector balance test, inspect regulator operation (check vacuum line and return hose), check fuel pressure

Check fuel quality.





IGNITION SYSTEM MALFUNCTION Check SPARK PLUGS for proper heat range.

Check for advanced spark timing.



ENGINE MECHANICAL Check for carbon buildup on pistons. Remove carbon with top engine cleaner. Follow instructions on can.
Check for excessive oil entering combustion chambers.



TRANSMISSION MALFUNCTION Check for proper transmission shift points.

Check for proper Torque Converter Clutch (TCC) operation.