What could cause engine knocking?

Engine knocking, also known as detonation, occurs when fuel in the combustion chamber ignites prematurely or unevenly, leading to a knocking or pinging sound. This condition can arise primarily from using low octane fuel or having improper ignition timing.

Low octane fuel cannot withstand the high pressure generated in modern engines, especially those with high compression ratios. When low octane fuel ignites too early, it causes a violent combustion process that results in knocking. Similarly, if the ignition timing is set too advanced, it can also lead to premature ignition of the air-fuel mixture, which creates the same knocking sound.

Understanding the relationship between fuel octane ratings and ignition timing is crucial. The right octane rating for an engine depends on its design and compression ratio; using a fuel with a lower rating than recommended can lead to significant performance issues, including knocking. Furthermore, the ignition timing must be adjusted accurately to prevent early ignition, ensuring smoother and more efficient combustion.

Other options, while they can influence engine performance, do not directly lead to knocking in the same manner. Excessive fuel pressure might cause issues like flooding or poor performance, but not necessarily knocking. High oil temperature and excessive oil viscosity can lead to lubrication problems and engine wear, but they