What Are the Causes of Engine Cylinder Scoring?
1 Answers
The causes of engine cylinder scoring are numerous and can be broadly categorized into usage-related and quality-related factors: 1. Quality: Poor lubricating oil or substandard component quality. 2. Usage: (1) During assembly, whether the cylinder liner size is incompatible with the cylinder block and piston. (2) Poor sealing of the air filter, reducing filtration efficiency and allowing dust, sand, and other impurities from the air to enter the cylinder, causing abrasive wear. Tests show that ingesting a few grams of dust daily can increase cylinder liner wear by more than 10 times. (3) Poor break-in. New or overhauled engines have microscopic irregularities on the surfaces of cylinder liners, pistons, and piston rings, making it difficult to form an oil film. If subjected to heavy loads immediately without proper break-in, cylinder scoring and other failures are likely. (4) Frequent cold starts. During cold starts, lubricating oil has high viscosity and poor flowability, making it difficult to form an effective oil film on the cylinder walls. Research indicates that diesel engines operating under load with coolant temperatures below 30°C experience 5–7 times more wear on cylinder liners and other components compared to normal operating temperatures. (5) Engine overheating. Poor cooling system maintenance or overload operation leads to excessively high temperatures, which not only reduce the mechanical strength of components but also prevent the formation of an oil film on the cylinder walls. Thermal expansion of pistons and other parts can cause them to seize in the cylinder liner, often resulting in partial piston melting, damage to the cylinder liner walls, and forced engine shutdown.
