What are the causes of cylinder scuffing in car engines?

[McLena]

Below are the causes of cylinder scuffing in car engines: 1. Overheating of the engine coolant due to a lack of water in the cooling system, preventing the coolant from circulating and dissipating heat, leading to excessive engine temperature. In such cases, some coolant may evaporate. If not replenished for an extended period, once the water pump fails to pump water, the engine will overheat due to water shortage. If the sealing performance of the cooling system is compromised, causing severe coolant leakage and resulting in a high-temperature condition due to water shortage, such as excessive wear of the water pump seal or cracks in the cylinder block. 2. Poor performance of the engine lubrication system: Insufficient engine oil reduces the oil pump's output, leading to a drop in oil pressure. This causes the crankshaft and bearings to lose normal lubrication conditions. Additionally, the cylinder liners and pistons experience dry friction due to reduced splashed oil, resulting in cylinder scuffing. 3. Poor performance of the engine fuel supply system leading to cylinder scuffing: If fuel injection timing is too early, almost all the fuel is injected into the combustion chamber during the compression stroke. As the piston moves upward, when the temperature in the cylinder reaches the fuel's auto-ignition temperature, the fuel ignites almost simultaneously. Some fuel vapor, surrounded by exhaust gases, cannot access oxygen and undergoes secondary combustion during the exhaust process. Post-combustion can easily cause the diesel engine to overheat, and in severe cases, lead to cylinder scuffing and other accidents.