Causes and Prevention of Engine Cylinder Scoring (2) scoring
Cause analysis of engine cylinder scoring: There are many reasons for cylinder scoring, generally speaking, there are three aspects: use factors, assembly factors, and manufacturing and processing factors.
2.1 Factors of use
(1) In the early period of new vehicle operation (including after major repair) when the running in is not carried out as required, due to the rough machined surface of the parts, there are certain errors in the shape and assembly position after machining, and the fit clearance is also small, so the wear and mechanical losses of the parts are large. In this period, if the vehicle is not driven according to the regulations, it will cause early wear of the engine, and in serious cases, a cylinder scoring accident will occur. Therefore, when driving in the running in period, the running in regulations must be strictly observed to ensure the running in quality. The main provisions include: reducing the loading weight, limiting the speed, selecting high-quality fuel and lubricant, driving on better roads, driving correctly and strengthening the running in maintenance.
(2) Improper use of lubricating oil General automotive engines have high heat load, high temperature and harsh working conditions, so appropriate lubricating oil shall be selected according to regulations. If the lubricating oil is not selected according to the specified requirements or the viscosity is not appropriate, the engine will be subject to scuffing and bush burning. This is because the viscosity of lubricating oil is too high and its fluidity is poor. Especially when starting at low temperature, it is not easy to reach the friction surface quickly, which accelerates the wear of the engine; If the viscosity of lubricating oil is too small, it is easy to cause the loss of lubricating oil from the friction surface, which cannot form a reliable oil film, and will also aggravate the wear of the cylinder. Therefore, the viscosity of lubricating oil should be properly selected. In addition, when changing the lubricating oil, replace the oil filter at the same time, otherwise it will directly affect and damage the oil quality, reduce the lubricating effect of the lubricating oil, and cause a cylinder scoring accident.
(3) Too low oil pressure and insufficient oil volume or too low main oil duct pressure may cause oil loss on the surface of the machine parts, interruption of the lubricating oil film, serious wear of various parts, and serious events such as cylinder scoring and bush burning.
There are two main reasons for low oil pressure: first, some thread hairs stick to the parts during engine repair, and are absorbed on the filter screen of the filter after being washed down by the engine oil during operation. Second, the oil passage hole was blocked carelessly when the oil filter was replacing the sealing gasket. Always observe the oil pressure gauge or oil pressure indicator during driving. If it is found that the pressure is lower than the specified pressure, especially when the pressure suddenly drops sharply, stop the vehicle in time and drive after proper treatment.
