Recently, some motorists have been complaining about why the car starts to rattle after driving for a long time. I can't stand the noise. The engine noise will be too loud, many car owners have been troubled by this problem. What is the cause of the engine noise?
1. There is carbon deposition
Because the old engine oil is used more and more thinly, there are more and more carbon deposits. When the oil is thin, it is easy to shift the oil, resulting in more and more carbon deposition and loss of a lot of power. When the new oil is replaced, the engine can not adapt to the viscosity of the oil, which may increase the speed and cause the engine noise.
2. Sound insulation
If you listen to the engine running normally outside and feel the noise is too loud when sitting in the car, it means that the sound insulation effect of your vehicle is poor. The seal of the vehicle should be checked for signs of aging. Or increase the sealing effect of the vehicle, and then try the noise.
As we all know, when the temperature of the coolant is too low, it is likely to have problems, and the noise of the engine will increase. This should be checked and replaced to avoid other problems.
4. Shock absorber
We all know the function of shock absorbers. Generally, we can feel whether the shock absorbers are good or not when passing the speed bumps. When there is a problem with the shock absorbers on the cars, there will be a big engine noise problem.
5. Deflagration and detonation
In the case of knock, that is, after the spark plug jumps, the combustible mixture at the end will spontaneously ignite. At this time, the flame center formed by the spark plug ignited mixture and the new flame center formed by the spontaneous combustion of the end mixture have opposite directions, and propagate at the speed of impact, producing sharp cylinder knocking sound and increasing engine noise.
6. Psychological function
People's hearing has errors in different environments. From the technical point of view of oil viscosity, the noise of engine oil with viscosity of 20 and 30 is slightly higher in urban driving, while it is slightly lower in normal driving at high speed. The oil with viscosity of 40 and 50 will make a little less noise when driving in the urban area, but it will be slightly higher when driving at high speed. Of course, if you want to really distinguish the size of the noise, you have to test it with a decibel meter