After parking, you often hear "dada" abnormal noise. Is it broken?

New car Chronicle 2022-05-14 14:53:16 阅读数:552


the other day , Xiaobian found that a netizen asked a question when browsing the auto forum :

They said they had just picked up the car by themselves , After parking and flameout these days, I suddenly heard that the chassis always makes some noise “ dadada ” Abnormal sound of , I wonder what's wrong . But because I don't know much about cars , I also feel that the new car hasn't been driven for a long time and shouldn't have problems , So go to the forum for advice .

actually , Similar questions have been raised in various auto forums , This abnormal noise is usually normal , Why do you say that ? Xiao Bian will tell you today .

Flameout heard “ dadada ” Abnormal sound , Don't panic !

actually , Such a strange noise is Because after the vehicle stalls , The sound of some metal parts due to thermal expansion and cold contraction , It's normal , You don't have to worry about . and , Usually “ dadada ” Abnormal noise is more likely to occur in the environment with low outdoor air temperature , It usually lasts 2-3 It disappears in seconds .

Everybody knows , When the vehicle is in use , The biggest source of heat is the powertrain system on the car . Once the vehicle is ignited , Engine body 、 Intake manifold 、 exhaust pipe 、 The temperature of key components such as turbine increaser will rise rapidly .

The powertrain system is in daily work , The temperature of these parts is not the same . For example , The temperature of the engine block generally does not exceed 100°C, The working temperature of the exhaust pipe will soar to 400~500°C, The temperature of the three-way catalyst on the exhaust pipe is as high as 600°C.

You may have had such an experience when driving , When the car engine is idling , If you're going to get something in the trunk , I happened to be standing at the exhaust pipe , Your feet may be scalded by the exhaust gas from the exhaust pipe .

It is precisely because the working temperatures of these metal parts are high and low , Therefore, the range of thermal expansion and cold contraction of these parts is also very different .

When we park the car and turn it off , The total achievement of the whole power is equivalent to stopping work , Under the influence of ambient temperature , Each part will gradually cool , At this time, the temperature of exhaust pipe and three-way catalyst with high temperature drops faster , This will lead to greater metal deformation .

The temperature of the engine block decreases relatively slowly , Due to the difference of deformation amplitude between them , It will squeeze at the connection between them , At this point, you can hear this... From the chassis “ dadada ” The sound of .

If there are these abnormal noises , Be alert

All say “ Toothache is not a disease , The pain is terrible !” This sentence is the same when you put it on a car , Take abnormal noise for example , We usually encounter all kinds of abnormal noises when driving , This situation is more obvious in old cars .

Abnormal noise sometimes, although it's not a disease , But it affects our driving experience to a great extent . Yes, of course , Some abnormal noises are actually precursors of car failure , If we don't check , The consequences will be more serious . Here are some common car abnormal noise problems , For your reference only .

1) Abnormal engine noise

This kind of abnormal noise usually comes from under the engine hood , If it's metal piercing sound or wind howling abnormal sound , Then you have to be careful . This abnormal noise indicates that there is a problem with a part of the engine , Mainly due to wear . This situation is common in old cars that have been driving for many years , And cars that don't pay attention to maintenance at ordinary times .

Give a few common examples of abnormal noise , For example, the foot glue of the engine is the rubber block between the engine and the frame , It is used to reduce the vibration and buffer of the engine during working , Once these foot glues are aged or loose , The engine will shake , Thus producing abnormal noise .

There are also serious abnormal noises , For example, the engine lacks cylinders 、 The cylinder makes a strange noise , It means that one or more cylinders of the engine are not working properly , Or it is due to poor lubrication conditions inside the cylinder block , Excessive wear of piston and cylinder wall , The clearance fit tolerance between piston and cylinder wall exceeds the normal range , triggering “ Dangdangdang ” Abnormal sound of .

2) Abnormal noise of gearbox The gearbox connected to the engine may also make abnormal noise , If there is... Inside the transmission during driving “ rustle ” The sound , Then you have to be vigilant , Generally speaking, it is also caused by lack of maintenance .

Nowadays, household cars generally use automatic transmission , In fact, there is lubricating oil inside the gearbox , These oils will fail if they are not replaced for a long time . There is no protective layer between the gears inside the gearbox , While aggravating the wear of parts, it will also produce abnormal noise , If not repaired in time , It will damage the planetary gears of the automatic transmission 、 Differential and other components , The consequences are serious .

3) Abnormal tire noise We usually hear tire noise while driving , This is normal , But if you hear an abnormal noise other than tire noise , Be careful .

Abnormal tire noise, if it is “ Make love ” Sounds like that , And rhythmic , And if the speed is fast and the frequency is high , Most of them are tire tread deformation 、 Drum bag 、 Severe wear or insufficient tire pressure , At this point, if you continue driving , There will be danger .

4) The brake sound We usually drive when we step on the brake pedal , The vehicle may make a harsh and abnormal noise , This is actually reminding you , It's time to check the braking system .

The braking system is mainly composed of brake disc and brake skin , If... Occurs when you step on the brake “ squeak ” The noise of the , It's mostly because the service life of the brake skin has come , It has exceeded its use limit .

Of course , If it's an old car that has been driving for many years , The brake discs may also be worn , When this happens , Car owners should go to a professional garage for maintenance as soon as possible , Otherwise, once the braking system fails , The probability of accidents will be very high .

5) The steering wheel makes a strange noise We sometimes have when we're going in the direction “ Creak. Creak ” Abnormal sound , This may be caused by the thermal expansion and contraction of plastic parts on the steering wheel . Of course , Another situation is that the abnormal noise comes from the foot , For example, the ball joint of the tie rod is aged .

If the steering rod ball joint is aged , Then it will cause the shaking and sound of the car steering wheel , In this case, the ball joint of the tie rod is usually replaced , And it can be repaired by four-wheel alignment after replacement .

To make a long story short , Don't panic in case of abnormal noise , It's always right to identify before overhaul , It's not necessary to be overly sensitive to abnormal noise , After all, some noise can't be avoided . But if you encounter these abnormal noises mentioned above , So Xiaobian wants to remind you to pay more attention to your car .

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