Engine knock, also known as pinging or detonation, is a common problem faced by car owners. It refers to the sound of metal striking metal in the engine, which is caused by premature ignition of the fuel-air mixture. Some synonyms for engine knock include engine ping, engine pock, engine clatter, engine rattle, engine knock-knock, engine thud, engine thump, and engine clunk. The severity of these sounds varies, ranging from a light tapping to a loud banging noise. To avoid engine knock, it is important to use high-quality fuel and maintain the vehicle's engine properly. In case of persistent engine knock, it is advisable to get the car inspected by a professional mechanic.