How to maintain abnormal engine noise? What to do if there is an abnormal noise after engine mainten

I believe that many car owners will encounter such a problem after maintenance, after routine maintenance, the engine sound is louder or abnormal than before maintenance, and the staff will generally tell you that this is a psychological problem. However, there are many reasons for the loud engine sound, and today we will talk about what causes the engine to make abnormal noise or louder sound after maintenance.

1. Change the engine oil of different brands.

The change in engine sound after maintenance is mostly due to the fact that we have changed different brands of oil. Engine oil is made up of base oil and additives, with base oil being the base and additives being the core. Each brand has different guidance formulations, such as high or low levels of PAO (polyolefins) in base oils, which will have an impact on engine noise; For example, the shear resistance of synthetic oil PAO (polyolefin) is different from that of MPAO (metallocene polyolefin), and the engine noise will not be the same under different working conditions.

It is not accurate to judge the quality of engine oil based on sound alone. Because some engine oils can make the engine sound relatively good at medium and low speeds; There are also some that have a "relatively beautiful" sound on the medium and high turns; Therefore, it is sometimes said that there is no best engine oil, only the most suitable oil for your car.

2. Changed the engine oil of the same brand and different grades.

Although it is the same brand of engine oil, the formula of different grades of engine oil is also different. In terms of base oil, the high-temperature performance of mineral oil is worse than that of synthetic oil; In terms of oil viscosity, the use of high-viscosity engine oil is prone to idle sound, while the sound is quieter than that of engine oil with low viscosity at higher engine speed; Low-viscosity oils, on the other hand, may have a relatively low idle sound, and a relatively loud sound when the engine speed is increased. For example, the content of PAO in different grades of engine oil of the same brand is also different, resulting in different sound levels.

We know that only those that use all PAO base oils can be truly called fully synthetic engine oils.

3. Excessive engine oil.

Excessive oil filling during maintenance will increase the load on the engine, and too much oil is also a common cause of dull engine sound and poor power. In the usual maintenance, pay attention to the oil scale to prevent excessive oil.

Fourth, too much carbon and oil sludge.

In addition to engine oil, other aspects will also cause abnormal engine noise after maintenance, such as carbon deposits and sludge inside the engine will also increase the engine sound. For example, if you often drive at low speed in urban areas, carbon deposition will become more and more serious, such as carbon deposition at the fuel injector, running a few times at high speed, which can reduce the generation of carbon deposition. In addition, depending on the label of the engine oil, the engine noise will also be different at idle speed and acceleration.

Summary: Therefore, in daily maintenance, try not to change the brand and label of the engine oil frequently; In the maintenance, it should be added according to the amount of oil in the maintenance manual; In daily driving, it is necessary to often pull the highway.

The engine is abnormal, pour some water and try it.

1. The engine has abnormal noise.

Symptom description: There is a lot of abnormal noise in the engine compartment, and most people also judge it to be the abnormal noise of the engine compartment by the sound**, which is usually a metal screeching sound or a howling sound.

Solution: The abnormal engine noise indicates that the technical status of a certain mechanism of the engine has changed. It is mainly caused by excessive wear and tear of some parts or improper assembly and adjustment.

Some abnormal noises can still predict that the engine will be damaged accidentally, so when the engine has abnormal noise, it should be repaired in time to prevent the fault from expanding.

It should be reminded that if it is an abnormal noise in the engine, most of the owners will not be able to solve it by themselves, and it is best to send it to the factory for maintenance.

2. There is abnormal noise in the gearbox.

Symptom description: If there is a "rustle" sound inside the gearbox while the car is driving, and there is no more after pressing the clutch or accelerator, there will be a whistle-like sound when changing gears.

Solution: There are many transmission parts, and the reasons for the sound are more complex, so we should pay attention to whether it is related to a specific speed, such as some planetary teeth that sound at about 50km h.

Whether it is related to certain gears, which is very important for judging the failure of the transmission, if a certain gear sounds, it must be related to the components that affect the transmission of the gear; If all gears sound, it is often a common meshing shaft failure or a lack of oil in the transmission. Whether it is related to specific actions, such as increasing and decreasing gears, starting, rapid acceleration, sharp deceleration, turning, etc., are effective means to judge abnormal noise, among them, changing speed and direction are particularly important for judging the rear axle fault.

If the abnormal noise of the transmission is obvious, it is recommended to send it to a professional repair shop to check the faulty parts, and then replace them.

3. There is abnormal sound of wear.

Symptom description: When driving on the accelerator or brake, there is always some abnormal noise in a certain part of the body, the sound is not loud, and it does not affect normal driving, but it always makes people worry a little about the failure of the body.

Solution: The abnormal noise of the door is mainly caused by the lack of lubrication, but it is necessary to judge whether it is the position of the door hinge or the glass regulator, door lock mechanism, handle mechanism, etc. inside the door. In the case of door hinges or limiters, special door hinges and slide grease can be used, while special door attachment grease is used for lubrication of glass regulators, door locking mechanisms, handle mechanisms, etc. inside the door.

In terms of brand selection, try to choose the commonly used brands in 4S stores, such as German Marty, Kluber, Tiger Head Hotolube, Fox, etc. It is not advisable to use engine oil or ordinary butter, it will freeze in winter, and the harmful smell will affect your health.

1. Excessive oil addition. If the oil is added too much when adding oil, at the upper limit of the oil dipstick, it will cause the amount of oil to increase when rotating and make the noise louder. It can even make the vehicle weak when accelerating, and there is a phenomenon of blue smoke when burning engine oil.

2. Change different brands of engine oil. After maintenance, the noise of the car becomes very loud, which may also be caused by changing different brands of engine oil, because the guidance formula of each brand of engine oil is different, so it will have a different impact on the noise.

3. During maintenance, the iron engine guard plate or other things were moved. If the iron engine guard plate is not tightened with screws when the car is maintained, it will cause noise when the engine rotates slightly and collide with the guard plate, and if other parts are not installed in place, it will also cause noise. In order to avoid this situation, it is necessary to go to a professional place for maintenance.

Normal maintenance does not involve the engine part, so the probability of abnormal noise is very low in the engine, it is best to find a maintenance worker to judge, because abnormal noise is divided into many kinds.

1. Abnormal sound of cold start.

Many car owners will hear the abnormal sound of "da-da" in the engine compartment when the car starts cold, in fact, this "da-da" abnormal sound is caused by the oil pump not fully establishing the oil pressure during the cold start, resulting in the lack of lubrication of various components. Under normal circumstances, when the engine has been running for a period of time, the rattling noise will disappear.

2. The carbon canister solenoid valve is working with abnormal noise.

The function of the solenoid valve of the carbon canister is that when the engine starts, the solenoid valve installed between the canister and the intake manifold is opened, and the gasoline vapor adsorbed in the canister is brought into the cylinder together with air to participate in combustion. This not only reduces emissions, but also reduces fuel consumption. This part also makes a clicking sound during operation.

The above two are normal engine clattering sounds, so the clatter sound of the car's cold start is not always a failure, and there will be no hidden danger of overhauling the engine.

3. The foot glue is aging or loose.

The foot glue is the rubber block between the engine and the frame. Its function is to reduce the vibration and cushioning of the engine when working, and to have the effect of fixing the engine. Once these foot glue are aged or loose, the engine will shake, and in serious cases, there will be a "click" abnormal sound, which only needs to be replaced with a new foot glue.

4. The mixture is too thick.

When the engine mixture is too thick, the phenomenon is: it is difficult to accelerate after starting, and the engine runs unevenly; black smoke from the exhaust pipe, a rattling sound from the engine, and sometimes a gun; Engine power decreases, fuel consumption increases. This is mostly related to carbon deposits, filter clogging, etc., and generally does not need to be overhauled.

It may be that some parts are not assembled during assembly, and if the abnormal noise persists, it is recommended to send it back for re-disassembly inspection.

First, confirm whether there is a problem with the assembly, then listen to the sound coming from there, and then check to see if there is a problem with the assembly.

Yesterday the car just finished maintenance, but there was a big noise in waiting for the traffic light to hang the forward gear, the n gear was gone immediately, and there was a sound on the bumpy road, which rider knew what was going on yesterday The car was just maintained, but there was a big noise in waiting for the traffic light to hang the forward gear, the n gear was gone immediately, and there was a sound on the bumpy road, which rider knew what was going on The automatic transmission has an abnormal sound, and there are many traces, it is not the internal valve body that is damaged, but the stubborn dirt and impurities inside, In particular, the dirt and impurities inside the valve body accumulate to form a blockage, resulting in the inability to effectively adjust the oil pressure, resulting in the occurrence of frustration and impact and gear slippage. At the same time, the problem of high temperature of the gearbox cannot be ignored. According to the Automatic Transmission Repair Association, it is called

More than 90% of all faulty automatic transmissions are caused by overheating. "High temperatures can damage the quality and friction characteristics of the automatic transmission fluid, increase friction and wear, and transmission noise will follow, as well as sludge (impurities or dirt) can be generated inside the transmission (e.g. valve body), causing the transmission to stun and shock. If the temperature exceeds 120 °C, the rubber sealing material will begin to harden, eventually leading to leakage and reduced hydraulics.

If the temperature is higher, the gearbox starts to slip, which in turn causes the temperature to rise even higher. (Audi and other high-end models will call the police and enter the transmission protection mode) If it is not solved in time, the transmission will be scrapped. Therefore, only by removing the stubborn dirt and impurities in the gearbox and effectively controlling the working temperature of the gearbox can the gearbox problem be completely solved and prevent its recurrence.

How to solve the abnormal engine noise? The engine is an accessory on a car that does the same thing on a car as the heart does on the human body. What went wrong with the engine is also a matter of great concern to the owner.

Today, Bian Xiao will take you to see what is the cause of abnormal engine noise.

The causes and treatment methods of abnormal engine noise.

1.If it is a cold start abnormal sound, this means that the engine will have a great sense of vibration and clicking noise after a long time of stopping, which will make the oil flow back to the oil pan, so the oil pressure cannot be quickly established when starting, and the internal accessories cannot work normally, resulting in the engine.

2.If the engine is not lubricated enough due to the use of unsuitable oil, which causes friction and abnormal noise, in this case, only the appropriate oil needs to be changed.

3.If the belt is not tightened enough, the engine will make a screeching sound. Just adjust the tightness of the belt.

4.If the engine is a backfire fault, it is because the engine valve has too much dirt or carbon deposits, and the engine will produce abnormal noise, and incorrect timing adjustment will produce abnormal noise. Simply clean the valve carbon deposits and adjust the timing.

5.Using mislabeled fuel can cause the engine to vibrate violently and make abnormal noises. Just choose the right label for the fuel.

6.Loose squeak in the external attachments that hold the engine in place or are connected. Tighten the relevant accessories and replace the damaged accessories.

7.When the inlet pipe leaks, the gas will be emitted from the leakage, causing vibration and abnormal noise. First, check the exhaust pipe and replace it if it is damaged.

In short, when there is an abnormal noise in the engine of a vehicle, the first thing to determine is what causes the abnormal engine noise. If you confirm that there is no danger, you can continue driving, or if you are in danger, you can continue driving, you can slow down and drive slowly to a nearby repair shop for maintenance.

1. I will hear the sound of the engine in general. First of all, the problem of the motor air conditioning belt and tensioner can be sprinkled on the belt, if it does not sound, it can be judged that there is a problem with the belt or tensioner. Or professional stethoscopes, iron rods, etc. auscultate crankshaft wheels, air conditioning wheels, motor wheels, tensioning wheels and other swing wheels, pay attention to safety.

2. Check whether there is oil leakage at the front and rear oil seals of the crankshaft, and eliminate the abnormal blowing sound caused by the positive pressure of the crankcase, so as to prevent the oil injection from hurting people when the oil filling port is opened in the third step.

3. When idling and chirping, slowly open the oil filler cap or pull out the oil dipstick to see if it will call again and whether it will suck the oil filler cap. If it is not called, it can be judged that the negative pressure of the crankcase is too large or the quality of the oil seal at the front and rear of the crankshaft is caused by the inhalation and chirping noise from the oil seal.

4. The negative pressure of the crankcase is large: if the negative pressure of the crankcase is large, the oil cap can be sucked or the repair shop measures the negative pressure value, which means that the negative pressure is large. There are 2 reasons, one is that the exhaust valve is damaged, and the other is that the crankcase air supply pipe is blocked.

Generally, the exhaust valve is damaged and replaced. Unclog the crankshaft air supply pipe.

5. Oil seal quality: If the negative pressure value is normal, it is a problem with the quality of the oil seal (the front and rear oil seals of the crankshaft are different).

6. Why does it not sound when refueling at idling: when idling: the throttle opening is small, and the negative pressure behind it is large, in the case of damage to the exhaust valve, blockage of the air supply pipe, and damage to the oil seal, the suction of the crankcase is large, and it will suck air from the oil seal into the crankcase, and chirp.

When refueling: the throttle opening is large, and the negative pressure behind it is small, in the case of damage to the exhaust valve, blockage of the air supply pipe, and damage to the oil seal, the suction power of the crankcase is not very large, and it will not suck air into the crankcase from the oil seal, and it will not chirp.