Detonation: A violent explosion; also called combustion knock. This usually occurs near the end of the combustion process when highly compressed, high-temperature end gases spontaneously ignite, ...

Like much in life, the difference between detonation and pre-ignition, and their effects, comes down to timing. Both refer to a situation when an engine's fuel/air mixture combusts at the wrong time, ...

When your car starts making a metallic knocking sound under the hood, you'd assume it could only be one thing: the engine. However, there are two common culprits, and they're definitely not the same.