This is one of the worst sounds your car can make. Finally, the third source of a knocking-type noise can be the engine's ...

and gives power to all the electrical and lighting components of the car. Knocking Engine knocking, also known as detonation, happens with the air-fuel mixture in the cylinders detonates unevenly.

The engine’s knock sensor (or sensors) detects preignition and detonation, potentially damaging forms of abnormal combustion. Though full-blown knocking and pinging are audible to the human ear ...