What Does Engine Cylinder Scoring and Bearing Burning Mean?
2 Answers
Engine cylinder scoring refers to vertical scratch marks appearing on the cylinder walls of an engine; engine bearing burning means severe scratches and abrasions on the journal surface, which oxidize and turn blue. Below are some related expanded contents: Causes of engine cylinder scoring: Cylinder scoring is related to engine lubrication. If the engine lacks oil, the oil has been used for too long and its viscosity is insufficient, the oil passages are blocked, or there are too many impurities in the oil, all these can cause cylinder scoring. Causes of engine bearing burning: Bearing burning is mainly caused by insufficient lubrication or too small a gap between the journal and the bearing. When a sliding bearing is working, a very thin oil film is required between the bearing and the rotating shaft for lubrication. If lubrication is poor, direct friction occurs between the bearing and the rotating shaft, generating very high temperatures. Although bearings are made of special high-temperature-resistant alloy materials, the high temperatures produced by direct friction are still sufficient to burn them out.
Engine cylinder scoring and bearing burning refers to a combination of severe internal engine failures. Cylinder scoring means the piston has scraped or worn grooves on the cylinder wall, usually due to insufficient lubrication or overheating; bearing burning occurs when the bearing shells (those parts supporting the crankshaft) melt or wear out from high temperatures. In my years of repairing cars, I've seen many cases, mostly caused by old engine oil, cooling system failure, or prolonged high-speed driving leading to low oil pressure. Symptoms include engine smoke, power loss, and metallic grinding sounds. If not repaired promptly, the entire engine may be ruined. Repairs require disassembling the engine and replacing parts, which is very costly. Car owners should change the oil regularly, check coolant levels, and not wait for warning lights to appear before taking action, or they will regret it. Simply put, proper maintenance can prevent 90% of such problems.
