1. Learn to distinguish abnormal noises from reasonable noises
When it comes to abnormal car noises, it is difficult for ordinary car owners to distinguish which abnormal noises are faulty noises and which are abnormal noises reasonable. If you go to a repair shop to check for an abnormal noise, only about 20% of cars actually have a problem. There is obviously a difference between the noise of a model equipped with a turbocharged engine and the noise of a naturally aspirated engine; models equipped with a crankcase may also produce noise due to friction, some car owners may be affected by theirs; noise after contacting different cars. Lack of understanding of mechanical knowledge, confusing reasonable abnormal noises with a vehicle breakdown. So learn to identify abnormal car noises to avoidto waste time and energy.
2. How to identify car noise:
In actual work, due to the limitations of working conditions, it is difficult to use special instruments to measure the judgment of sounds to describe. and compare car noises. For example, the "squealing" noise caused by the dry friction of bearings, the "clicking" noise produced by excessive valve clearance, which is similar to the "clicking" sound of a small hammer hitting the ground in cement, etc.
1. Correctly distinguish between normal and abnormal sounds.
When the car is running, the vibrations of various mechanisms will make sounds of different kinds, but the sound does not mean that the car is defective. In order to avoid unnecessary disassembly, you must first distinguish what is normal. abnormal sounds and sounds. Normal vibrations of various system components (such as noise on the surface of the motor), gear impact noises when changing gears, intake and exhaust noises using gas as a work source, gear meshing noises, etc. are all normal sounds. Abnormal noises (abnormal noises) can be divided into light noises, normal noises and malignant noises according to their impact on car performance. Slight noises, such as the flashing sound of high voltage electrical leakage, the slight rolling noise of bearings, etc., generally have a small volume, the wear degree of the parts is not large, and it does not There is no significant change for a long time. Such defects can still keep the car without repair normal driving.
3. When diagnosing abnormal car noises, attention should be paid to creating good auscultation conditions and trying to eliminate interference from other noises so as not to affect the accuracyof judgment.
It is best to consciously amplify or reduce the sound, that is, use a screwdriver or other metal rod as a stethoscope to contact the sound part to amplify the sound , or use a single cylinder to cut off the fire to reduce the sound, to meet the diagnostic needs. The monitoring site must remain quiet to minimize human interference.
3. Below we list some common abnormal car noises that are easy to eliminate along with simple methods of identification and elimination.
1. There are abnormal noises in the body
Explanation of symptoms: When you drive and press the accelerator or brake, there are always abnormal noises from some parts of the body. .The sound is not loud and does not affect normal operation, but there is always a little worry that something is wrong.
Problem analysis : This problem usually occurs because the rigidity of the body is insufficient, causing the vehicle to deform while driving, the door and frame to rub or shake, or desoldering in some places causes friction between the plates. steel. , etc. .
Some cars also have louder wind noise. To a certain extent, this is related to the wind noise of the car. Depending on the shape, some cars may also cause abnormal noise if the body parts are not fixed well. Usually, tightening the screws can solve the problem.
Solution:
First check whether there are any loose objects in the trunk or on the rear seats that are easy to roll and make sounds, and exclude some items that are not securely attached and emit sounds. . noise.
If you notice that friction between doors and windows is causing abnormal noises, you canStick tape on doors and windows or put rubber on friction parts. You may be able to reduce or eliminate abnormal noises. , but the result is only a temporary solution and not the root cause of the problem. If none of the above problems are found, you should go to a regular repair shop for inspection and troubleshooting.
2. There are abnormal noises in the engine
Explanation of the symptom: There is a greater possibility of abnormal noises in the engine compartment. Most people also judge that abnormal noises come from the engine. engine compartment depending on the source of the sound, usually a metallic screech or hiss.
Problem Analysis: Abnormal noise coming from the engine compartment will include a loud whistling sound from the belt, which is usually caused by belt slippage. There will also be a high-pitched noisedry friction of metal parts when the engine is running, which is usually caused by damage to the bearings of the generator, water pump and power steering pump. If the sound of air leaking is caused by the engine running, it may be the result of a blocked engine; exhaust system, vacuum tube leak or rupture.
Solution: Abnormal engine noise indicates that the technical condition of a certain engine mechanism has changed. This is mainly due to excessive wear of certain parts or poor assembly and adjustment. Certain abnormal noises can predict the possibility of accidental engine damage. Therefore, when abnormal noises occur in the engine, they should be repaired in time to prevent the fault from extending.
It is worth remembering that if there is an abnormal noise in the engine, the car owner is unlikely to be able to solve it himself and is preIt is feasible to send it to the factory for servicing.
3. There is an abnormal noise in the gearbox
Explanation of symptoms: If there is a “rusting” sound inside the gearbox while the car is driving, but it disappears after the clutch or accelerator is pressed, replace it. A whistling sound will be heard when changing gears.
Problem analysis: If the source of the noise encountered while driving is the gearbox, it may be due to wear of the gearbox bearings or gears, or to points rolling. If the transmission makes abnormal noises when shifting at high speeds, the transmission oil may contain metallic powder, indicating excessive wear of components such as the gear belt clutch. brake of the gearbox.
4. There are abnormal noises in the tires
Symptom description: the tires aremake rhythmic noises, and the faster the vehicle speed, the higher the frequency.
Analysis problem: When a car tire contacts the ground, it will produce various noises of different strengths and weaknesses depending on the type or irregularities of the road, the speed of the car, the type of tire and the air pressure of the tire itself. Therefore, no matter how perfect a car is, it cannot completely eliminate the noise generated by tires and ground while driving.
5. The engine guard makes an abnormal noise.
Explanation of symptoms: The engine guard has been installed for some time, but after a ride in the suburbs, there was a noise at the skid plate at my return. Strange noise.
SolutionSolution: Screws tend to move in cars that move frequently. If you often hear "pop, pop, pop" noises coming from the air intake grille, in addition tothat the grille is really loose, the car owner should always check whether the engine guard. the plate screws are loose, or the motor protection plate and the bottom plate are loose, causing abnormal noise. In addition to tightening the screws, you should also place cardboard objects in the abnormal sound area to easily eliminate the abnormal noise.
6. Brakes make abnormal noises
Symptom description: The vehicle makes relatively loud noises and abnormal noises when the brakes are applied.
Problem Analysis: Of course, abnormal noise when braking may also be caused by other reasons, such as improper use or deformation of the brake disc material, hardness and brake friction pad pores