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. Check the following systems and components.



COOLING
^ For obvious over heating problems
^ FAN OPERATION
^ AUXILIARY COOLING FAN
^ Low engine coolant level and leaks
^ WATER PUMP: Operation, loose belts
^ Restricted air flow to radiator or restricted coolant flow.
^ THERMOSTAT: Faulty or incorrect.
^ Correct coolant solution - should be a 50/50 mix of anti-freeze (coolant) and water.



COMPUTER INPUTS/OUTPUTS
^ Electronic Fuel Injection(EFI) control unit




FUEL
^ LEAN FUEL/AIR MIXTURE: Test fuel pump pressure and volume output.
^ FUEL INJECTOR: Fuel injector spray pattern, clogged, or stuck injector.
^ FUEL QUALITY: Poor or contaminated fuel, proper octane rating.



IGNITION
^ SPARK PLUGS: Proper heat range.



ENGINE/TRANSMISSION
^ For incorrect basic engine parts such as cam, heads, pistons, etc.
^ For excessive oil entering combustion chamber.
^ Proper transmission shift points.