What is the reason for the abnormal noise from the transmission when the car is cold and the noise disappears after the car warms up?
1 Answers
The reason for the abnormal noise when the car is cold and the noise disappears after warming up is: when the car is cold, due to gravity, the engine oil is all in the oil pan and has not yet fully lubricated all parts of the engine. At this time, when starting the engine, there is no oil film between the components, especially in areas such as the cylinder head and valves. Without lubrication, abnormal noises will occur. After the car warms up, all parts are fully lubricated by the engine oil, and the noise will disappear. Reasons for the abnormal noise: noise caused by valve knocking; noise caused by the generator belt being too tight or too hard; noise caused by the generator belt slipping; noise caused by the timing chain loosening. Solutions: First, check whether there are any unfixed, easily rolling, and noise-making objects placed in the trunk or rear seats to eliminate noise caused by improperly secured items. Some abnormal noises can even predict potential serious damage to the engine. Therefore, when abnormal noises occur in the engine, they should be repaired promptly to prevent the fault from worsening. In addition to tightening screws, placing cardboard-like materials at the noise source can easily eliminate the abnormal noise.
