What Does Engine Knock Mean?

[EvaDella]

Engine knock is an abnormal combustion phenomenon, and the specific details are as follows: 1. When the pressure and temperature inside the engine increase, atomized gasoline explodes without being ignited, causing severe vibrations in the engine. 2. After the engine draws in a mixture of fuel vapor and air, the compression stroke does not reach the ignition point (the spark plug has not yet fired), yet the fuel-air mixture ignites and combusts on its own. The immense impact force generated by this combustion acts opposite to the direction of piston movement, resulting in engine vibrations. 3. Irregular metallic knocking sounds occur inside the engine. For example: clunking or rattling noises, or causing the engine to shake, or even noticeable vibrations in the vehicle body. The sound becomes louder when the throttle is fully open in high gear or when climbing a slope.