What is engine knock?

Engine knock, often referred to as "pinging" or "knocking," describes an abnormal combustion phenomenon that produces noise within an engine. This sound is the result of the air-fuel mixture igniting prematurely in the combustion chamber. Ideally, the mixture should ignite from the spark plug in a controlled manner, but when it ignites too early or in multiple spots, it causes pressure waves that create the distinctive knocking noise.

The presence of engine knock typically indicates issues such as incorrect fuel octane rating, engine overheating, or malfunctioning timing controls. It is a critical symptom that should be addressed, as prolonged knocking can lead to engine damage. Understanding this phenomenon is vital for diagnosing performance issues and ensuring proper engine operation.