Why the lubricating oil will become black

https://www.sdrboil.com/fully-synthetic-or-synthetic-turbine-oil-sp-5w-30.html

Why the lubricating oil will become black

Lubricating oil after a period of time, the color will become black, some owners will think that the oil has been seriously deteriorated, and will be replaced, but the lubricating oil black does not necessarily mark the deterioration of the lubricating oil, your this method will cause waste instead.

First of all, we need to know that the general oil are added to the clean dispersant, the purpose is to adhere to the piston on the film and black carbon washing down, so the lubricating oil after a period of time the color is easy to become black, but then the oil did not deteriorate. Why does the color of lubricating oil become black?

01 Why does the oil (lubricant) turn black when it is just changed?

(1) because in the oil change did not clean the engine, the previous oil in the oil sludge deposits in the oil pan and the engine inside, plus new oil due to the new oil in the role of the clean dispersant, so that some of the engine inside the sludge, carbon, gum, etc. dispersed in the new lubricating oil so that it is black.

(2) lubricating oil black and lubricating oil filter, air filter quality and replacement cycle, if the air filter is poor quality or replacement is not timely, dust and impurities will enter the cylinder adhesion in the cylinder wall and then mixed into the lubricating oil contamination of lubricating oil.

(3) lubricating oil black is not necessarily poor lubricating oil quality, because high-quality lubricating oil contains cleaning and dispersing agent, it can clean and disperse the engine inside the previous presence of gums, varnish, carbon, etc., so that it is suspended in the new oil, so that the oil is more likely to be black.

(4) poor quality or poor quality lubricating oil will also appear soon after the use of lubricating oil black, because poor quality lubricating oil oxidation, high temperature resistance is poor, lubricating oil is easy to deteriorate.

02 How to recognize the good and bad motor oil (lubricant)!

(1) smell method, pull out the oil ruler close to the nose to smell, if there is a strong sour odor, that the oil has deteriorated, should be replaced.

(2) hand-twisting method, will take out the old oil with the thumb and forefinger repeatedly grinding, good quality feel lubrication, less abrasive debris, no friction. If you feel impurities, poor viscosity, or even astringent, should be replaced.

(3) color method, take a clean white filter paper (available good point of Kleenex), drop a few points of old oil on the paper, to be oil leakage, the quality of the oil is good no powder, dry and smooth by hand, and yellow infiltration with a clear, and the oil in the paper apportionment uniform. Dark black brown, impurities, should be replaced.

03 blackened oil (lubricant) can still be used?

   It is normal for the oil to turn black, and the change in color does not mean that the performance has changed. As long as the oil used is of genuine quality, the blackened oil can still be used.

      Warm tips: engine lubricant oil change period should be appropriate, too early will cause lubricant waste, too late and will increase engine wear, shorten the engine maintenance cycle and service life.