A knock sensor is a device used in internal combustion engines to detect the presence of knocking, which is an abnormal combustion event that can damage the engine. Knocking occurs when the air-fuel mixture in the cylinder ignites prematurely, causing a rapid increase in pressure that can damage the engine’s pistons, valves, and bearings.
Knock sensors are typically mounted on the engine block or cylinder head, and they use a piezoelectric crystal to detect the vibrations caused by knocking. When knocking is detected, the knock sensor sends a signal to the engine’s electronic control unit (ECU), which then adjusts the engine’s timing or fuel mixture to reduce or eliminate knocking.
