How to judge the engine oil from the engine oil color?

Engine oil after a period of time, the color will gradually darken, other colors are abnormal phenomenon. Why oil is black has four main items:

1, during the operation of the engine, the fuel will be incomplete combustion of gasoline olefin content is higher the more easily oxidized, and the formation of black sludge.

2, air filter effect is not good, adhesion of dust into the cylinder in the cylinder wall, piston ring was scraped into the oil pan and oil mixing.

3, piston ring and cylinder wall clearance is too large, resulting in a large number of high temperature gas comes into the oil pan to make oil oxidation.

4, each oil change does not clean the engine or does not change the oil filter element, new oil is not put clean waste oil pollution, new oil will be in the engine of gum, coke, sludge and other cleaning down, mixed with oil, make it black.

If the oil used for a period of time after the color appears to be gray, white, indicating that the filling oil mixed with water, and emulsification occurred. The basic performance of the engine oil has been completely lost, and the engine cooling system and the combustion system are leaking, so it is not suitable to continue to use it. Please contact the maintenance station immediately for thorough overhaul.