Detonation/Spark Knock/Pings

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



SYSTEM OR COMPONENT TO CHECK ACTION



COOLING CHECK Over heating problems:
- Low engine coolant level and leaks.
- Water pump operation, loose belts
- Restricted air flow to radiator or
restricted coolant flow.
- Faulty or incorrect thermostat.
- Correct coolant solution - should be a 50/50
mix of anti-freeze (coolant) and water.
- Fan operation.



FUEL NOTE To determine if the condition is caused by
a lean system, the vehicle should be driven at the
speed of the complaint. Monitoring block learn will
help identify the problem (Lean - Block learn greater
than 150).
CHECK FUEL PRESSURE
Related Tests, Information and Procedures
FUEL QUALITY and proper octane rating:




IGNITION CHECK SPARK PLUGS for proper heat range.
Spark Control system operation.
TIMING.
Knock Sensor




EMISSIONS CHECK EGR system and Valve operation.
THERMOSTATIC AIR CLEANER operation.




ENGINE/TRANSMISSION CHECK - Carbon buildup Remove carbon with
top engine cleaner. Follow instructions on can.
- For incorrect basic engine parts such as cam,
heads, pistons, etc.
- For excessive oil entering combustion chamber.
- Proper transmission shift points.
- Torque Converter Clutch (TCC) operation.