What's the matter with the loud engine noise after changing the automatic transmission oil for Fit?

The noise caused by engine oil change in Pacific Auto Network may be caused by excessive oiling, improper viscosity of engine oil, moderate carbon deposition, and the addition of inferior engine oil. It is also possible that the water temperature is too high, depending on whether the water thermometer is normal. If the noise is loud when idling, and the vehicle is idling at high speed, it is likely to clean the throttle, air intake and nozzle of the car.

1, it's common that the engine sounds louder after changing the oil. It may be that excessive oil filling will increase the resistance caused by crankshaft rotation and reduce the engine power, and at the same time cause the air-fuel ratio of the combustion chamber to change, increasing the chance of knocking, so the noise will increase.

2. Incorrect viscosity of engine oil When replacing with new engine oil, the engine can't adapt to the viscosity of engine oil, which may increase the speed and cause engine noise. At this time, it takes a period of running-in, and it will return to normal after adaptation. In addition, it may be that the viscosity of the oil is not suitable. If the viscosity of engine oil is too low, its lubrication degree is not enough, and engine parts wear and produce abnormal noise; If the oil viscosity is too high and the engine load is too high, it will produce noise.

3. The old engine oil with moderate carbon deposition is getting thinner and thinner, and the carbon deposition is increasing. When the engine oil is thin, it is easy to escape the engine oil, resulting in more and more carbon deposits. When replacing the new oil, the engine can't adapt to the viscosity of the oil, which may increase the speed and cause engine noise. It is suggested to use high-grade gasoline to start the high speed, and it is best to keep it above 2500 rpm, which should improve the situation. Of course, preventive cleaning can also be carried out.

(Photo/Text/Photo: Pacific Auto Network Q&A called Beast)