What is pre-ignition?
A. Pre-ignition is an uncontrolled ignition process in which the temperatures in the combustion chamber can rise to such an extent as to cause serious damage to the engine and the spark plug. Full-throttle operation can generate localized hot spots and cause pre-ignition at the following locations: At the tip of the spark plugs insulator nose On the exhaust valve On the protruding sections of the head gasket On loose deposits (ash and carbon residue) Pre-ignition of the air/fuel mixture can cause severe damage to an engine and this is one reason why the heat range of a spark plug is so important.
