BMW's common oil leakage phenomenon is not uncommon. More than 100000 vehicles are driven, which is generally caused by aging of some engine sealing washers. When there is a problem, we just need to simply replace the corresponding sealing ring. After inspection, it is found that there is water leakage, which is located under the booster pump of vacuum brake, that is to say, the water plug component. It is also a normal phenomenon that the water plug is aged under high temperature for a long time and causes leakage. If it is not seriously removed and sealed again, it is good. On the contrary, we need to replace the water plug component.
If the automatic gearbox is used for a long time (usually two years or 60000 km) without replacement, the oil will deteriorate; or the locking function of the hydraulic torque converter fails; or the radiator of the automatic gearbox is blocked or the radiator of the automatic gearbox is bent, the temperature of the automatic gearbox will be too high.
If the oil level is too low, the oil pump will draw in air to mix the oil with air; if the oil level is too high, the planetary gear and other rotating parts will be immersed in the gearbox, causing oil agitation. Whether it is too high or too low, it will lead to the deterioration of the automatic transmission oil, resulting in failure.