Automobile abnormal noise includes engine abnormal noise, clutch abnormal noise, transmission abnormal noise, main reducer abnormal noise, suspension system abnormal noise, braking abnormal noise, steering abnormal noise and body abnormal noise.

First, the common problems of automobile abnormal noise, it is difficult for ordinary car owners to distinguish which are fault abnormal noise and which are reasonable abnormal noise. When I went to the garage to check the vehicles with abnormal noise, only nearly 20% of the vehicles really had problems. There is a difference between models equipped with turbocharged engines; Vehicles equipped with engine guards may also generate noise due to friction; Some car owners may mistake reasonable abnormal noise for vehicle failure due to their ignorance of mechanical knowledge after contacting different cars. Therefore, learn to distinguish the abnormal sound of cars and avoid wasting time and energy.

Second, the identification method of automobile noise:

In practical work, due to the limitation of working conditions, it is difficult to measure automobile noise with special instruments, and we can only describe and compare automobile noise by judging the sound in daily life. For example, the "click" sound produced by dry friction of bearings, and the "click" sound similar to a small hammer hitting the cement floor caused by excessive valve clearance.

1, correctly distinguish normal noise from abnormal noise.

When the car is working, the vibration of various mechanisms will make various noises, but the noise does not mean that the car is faulty. In order to avoid unnecessary disassembly, it is necessary to distinguish normal noise from abnormal noise. The normal vibration sound of each system component (such as the noise on the engine surface), the impact sound of gears during gear shifting, the intake and exhaust sound with gas as the working source, and the gear meshing noise are all normal noises.

2. Abnormal noise can be divided into slight noise, general noise and malignant noise according to its influence on automobile performance. Slight noise, such as high voltage leakage flashover noise, slight looseness noise of rolling bearing, etc. Generally, the volume is low, the wear degree of parts is not great, and there is no obvious change for a long time. This kind of fault can maintain the normal running of the car without repair.

3, in the diagnosis of abnormal car noise, should pay attention to create good auscultation conditions, try to eliminate the interference of other noise, so as not to affect the accuracy of judgment.

It is best to amplify or reduce the sound consciously, that is, to use a screwdriver or other metal bar as the sounding part of the stethoscope to amplify the sound, or to use a single tube to cut off the fire to reduce the sound to meet the needs of diagnosis. The auscultation site should be kept quiet to minimize the interference of human factors.

Third, the source of abnormal sound:

Abnormal sound source 1: storage compartment. I believe that most car owners have no habit of sorting out storage compartments. The storage compartment that hasn't been sorted for several years must be full of messy items. In this case, no matter where the car goes, it will "jump" with the engine as long as the engine opens the items in the storage compartment. The abnormal noise you hear is probably caused by the vibration of the items in the storage compartment.

Abnormal sound source 2: transmission mechanism. In fact, the car will make a slight abnormal sound without fault, but how to judge whether the abnormal sound of the car is a fault or a normal phenomenon? It's actually quite simple. You just need to observe that if the noise becomes louder when the speed increases, it proves that there is something wrong with the automobile transmission system. The most effective solution is to see if there is a puncture in the car tire. If so, I suggest you go to a regular car 4S shop for maintenance.

Abnormal noise source 3: abnormal noise outside the car. If the abnormal noise you hear comes from outside the car, first check whether the doors and windows of the car are normal and see if there is anything in the trunk. Many times, the collision of objects in the car will also make the driver hear voices and think that the car is out of order. In addition, check whether there are sundries around the wiper, and if there are, clean them up in time to avoid affecting the normal use of the wiper.

Abnormal sound source 4: pulley. If you find that the car will make a "cough" sound from time to time during driving, everyone should check if there is anything wrong with the pulley of the car at this time. You know, the service life of automobile pulleys is about eight years. If the car pulley is not replaced for more than eight years, it will make a "cough" sound in the cold winter. If you want to replace the pulley, Bian Xiao suggests that you go to a regular automobile 4S shop for replacement. Don't do it yourself, or improper operation will cause damage to the car.

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