What are the causes of engine pre-ignition?

[Jayla]

Engine pre-ignition can be caused by carbon deposits, oil entering the combustion chamber, etc. Formation of hot spots in the combustion chamber: Hot spot theory suggests that design flaws or carbon deposits can create high-temperature spots in the combustion chamber. During high-load operation, these spots may exceed the ignition temperature, igniting the air-fuel mixture without spark plug activation, leading to excessive pressure buildup. Evidence supporting this theory includes the fact that engines are more prone to pre-ignition after prolonged use. Splashing of oil-fuel mixture into the combustion chamber: During piston movement, droplets of oil-fuel mixture may splash into the combustion chamber. These mixtures have a lower ignition point, forming pre-ignition nuclei that can ignite the entire combustion chamber. For example, in GDI engines, side-mounted fuel injectors facing the cylinder wall are more prone to pre-ignition than top-mounted injectors facing the piston.