What are the manifestations and causes of engine knocking?

[Journey]

Manifestations of engine knocking: You can clearly feel abnormal engine noise and vibration, which reduces engine output power, increases temperature, and raises fuel consumption. Causes of knocking: Excessive carbon deposits in the engine combustion chamber: Excessive carbon deposits in the engine combustion chamber not only increase the compression ratio (generating high pressure) but also create high-temperature hotspots or sparks on the carbon deposit surface, leading to engine knocking. Engine overheating: An engine operating in an excessively hot environment causes high intake air temperature, or poor engine coolant circulation, both of which can result in high engine temperature and knocking. Low octane rating of fuel: The higher the fuel grade, the stronger its anti-knock performance. Engines with high compression ratios have higher combustion chamber pressure. If fuel with low anti-knock performance is used, knocking is more likely to occur. Solutions for knocking: Reduce the ignition advance angle; use gasoline with the specified octane rating; clean carbon deposits from the combustion chamber; if knocking occurs when the car is going uphill, shift to a lower gear promptly; when starting the car, do not shift into direct gear too early; if knocking occurs due to excessive engine load, close the throttle slightly.