Knocking and pinging is generally caused by improper combustion in your engine, called “auto-ignition.” If the gasoline-air mixture auto-ignites somewhere in the cylinder (other than at the spark plug) just after spark ignition, the auto-ignition combustion wave can interact with the spark-initiated combustion wave, causing the vibration we hear as knock or ping. Increasing engine load, temperature, compression, spark-advance, air-fuel ratio and combustion chamber deposits all increase the tendency for an engine to knock.
Using higher octane gasoline reduces an engine’s tendency to knock. If excessive combustion chamber deposits are contributing to the knocking problem, you may benefit from adding a bottle of Techron Concentrate Plus to your next purchase of gasoline.