What are the causes of engine piston knocking?

[DiJesse]

Reasons for engine piston knocking: 1. Issues with the cooling system, such as cooling system leaks or insufficient coolant; 2. Engine oil leakage or excessive oil consumption, leading to oil deficiency; 3. High-speed or overload operation of the engine, causing excessive temperature; 4. Excessive clearance between the piston pin or cylinder liner; 5. Contaminated engine oil, resulting in poor lubrication; 6. Poor lubrication between the piston and cylinder, or the use of inappropriate engine oil. Methods to resolve engine knocking: 1. If knocking sounds occur in a low-temperature environment after starting the car and disappear as the temperature rises, this type of knocking can be temporarily ignored, and driving can continue; 2. If the knocking sound does not disappear and becomes more pronounced even when the engine temperature is normal, the owner should avoid high-speed driving and promptly stop to inspect, preventing potential traffic accidents; 3. If severe ovality, scoring of the cylinder is found after removing the cylinder head and extracting the piston, or if the clearance between the piston and cylinder is too large, the cylinder liner, piston, and piston rings should be replaced.