What is engine knock?
Engine knock is a sharp metallic noise, sometimes referred to as engine clatter or pinging, caused by the pre-ignition of fuel as it’s compressed in the cylinder, milliseconds before the normal spark plug firing. This condition typically occurs during acceleration, such as merging into highway traffic, or under heavy load conditions, such as pulling a boat or travel trailer. Under knock conditions, a vehicle will experience a reduction in power output as well as reduced fuel economy.
