Lubricating oil failure causes and discrimination methods
1. Causes of Lubricant Failure
(1) High temperature effect
① The lubricating oil is exposed to high temperature for a long time, it will oxidize and fail, and it will become black and thick.
② Corrosive substances inside the lubricating oil increase, such as acid substances formed during engine operation.
③ Increasing substances such as carbon deposits, sludge and paint film.
It mainly comes from dust, metal abrasive particles, leaks (fuel oil, water, etc.) in the air, lubricant oxides, and substances produced by the combustion of fuel.
(3) Additive failure
Some lubricating oils degrade due to the failure or exhaustion of additives in them. For example, running out of antiwear agents in lubricating oil manufacturers will reduce antiwear properties.
(4) Failure of viscosity index enhancer
Because of the long chain break of the organic molecules, it no longer has a viscosity-increasing effect.
(5) Failure of base oil
The base oil is the carrier of the additives, and the additives will not work if the base oil fails.
2. Judgment method of engine oil failure
Although there are national standards for deciding whether to change the engine's lubricating oil, most car owners or maintenance personnel change oil mainly based on the mileage / time of the car (manufacturer's regulations) and the color and viscosity of the lubricating oil. In fact, the above-mentioned methods are all unreasonable. For example, judging by color, some brand new lubricating oils appear black, and some lubricating oils may be blackened by adding too much detergent and dispersant. At this time, the lubricating oil has not failed, which may cause misjudgment to people with insufficient experience. A more convenient and effective way is to determine whether the lubricating oil has failed by means of filter paper or electronic equipment.