Operation CHARM: Car repair manuals for everyone.

Detonation/Spark-Knock/Pings

Definition: A mild to severe ping, usually worse under acceleration. The engine makes sharp metallic knocks that change with throttle opening.


POSSIBLE CAUSE ACTION

Lean operating condition Check computer controls.

Poor or contaminated fuel ^ Check for excessive alcohol content. Alcohol In Fuel Test
^ Recommend higher grade fuel

Incorrect fuel pressure Fuel Pump Functional Tests

Vacuum leak ^ Inspect vacuum hoses for proper routing and damaged lines
^ Check intake manifold, throttle body, etc.