KNOCK SENSOR

Controlled combustion is a pre-requisite for efficient, lowemission engine operation. Knocking occurs when the air-fuel mixture self-ignites prematurely. Sustained knocking combustion causes damage primarily to the cylinder-head gasket and cylinder-head. Engine management can reduce the risk of knocking by setting a later ignition point. The aim, however, is to obtain the maximum energy yield from varying qualities of fuel by selecting an ignition point that is as early as possible.

The knock sensor is mounted on the crankcase. It measures the structure-borne noise using a piezoelectric measuring element, and identifies knocking by its higher sound frequencies.