What are the five causes of cylinder scoring?
2 Answers
The five causes of cylinder scoring are: 1. The sliding contact area between the piston ring and the inner surface of the cylinder is too small, generating high temperatures; 2. Poor filtration performance of the air filter, allowing external dust and impurities to cause cylinder scoring; 3. Inferior material quality of the piston ring, making it prone to breakage; 4. Excessive viscosity of the piston ring lubricating oil, resulting in poor lubrication during cold starts; 5. Excessive overload and insufficient cooling circulation. Cylinder scoring is one of the common faults in automobile engines, where deep grooves are formed on the inner wall of the cylinder, causing the piston, piston ring, and cylinder wall to lose their sealing ability during friction. This leads to a reduction in cylinder compression pressure and loss of power.
I've experienced cylinder scuffing before, and the repair shop said insufficient oil lubrication is the most common cause. It could be due to a faulty oil pump or sludge buildup in the oil pan clogging the filter screen, preventing oil from reaching the cylinder walls and causing dry friction. Older cars especially need to be careful during winter starts when the oil is thicker and flows slower, which can further damage the engine. Another possibility is excessive piston expansion due to engine overheating, where the piston directly scrapes the cylinder wall. If you hear abnormal engine noises and see blue smoke, it’s likely a precursor to cylinder scuffing.
