Fault diagnosis and elimination of abnormal engine noise

The fault diagnosis and elimination methods of abnormal engine noise are as follows: 1. Abnormal noise caused by aging or loosening of the machine foot pad. The machine mat is generally installed in the middle of the engine and the body, connecting the body and the engine, and playing the role of fixing the engine.

The function is to play the effect of cushioning and shock absorption, once the foot pad is aged or loose, the engine shaking will be severe, resulting in abnormal noise.

In the case of uncertainty that the abnormal engine noise is related to the above system and mechanism, according to the diagnostic steps, first of all, start the engine to confirm the symptoms and distinguish the approximate abnormal noise, remember that after starting, the friction sound of "quack" came from the belt transmission mechanism at the front end of the engine, and the sound also accelerated during the acceleration process, but could not keep up with the rhythm of the engine when working, and confirmed the approximate symptoms and sound**, However, there are many moving parts that can cause abnormal noise at the front end (there is a belt transmission mechanism on the outside of the timing chamber cover and a timing mechanism inside), so it is not sure which moving parts are related to abnormal noise.

Normally, it is based on his voice, and in general, it may be the deviation of the bearing, or it may be that the magnetic inductance line is unevenly cut.

The cause of the abnormal engine noise is more complicated, it may be because the ignition timing is not right and causes the cylinder to knock, it is recommended to go to a professional repair shop for inspection and repair.

Fault diagnosis and elimination of abnormal noise of the engine, this is not a sentence or two can be clearly explained, this can only happen by contacting the repair shop.

Hello, regarding this issue, I personally think it is recommended that you better go to a car repair shop or a car shop for inspection and repair.

If you have any problems with the car, you still have to find a professional auto repair shop staff to help you take a look, because we are not particularly good at this aspect.

Abnormal noise needs to be diagnosed on the spot, and the approximate location is confirmed first.

The struggle for fault diagnosis and elimination in your life, I am enough to still depend on the actual situation to operate, generally speaking, to special maintenance, forever to find out.

This is a very professional question, if you want to learn systematically, it is best to find a school to learn auto repair all-round to figure it out.

If you want to diagnose and eliminate the abnormal noise in the engine, you can operate it through the engine inside it, and then you can click on its price to recover.

Engine abnormal noise: 1. Symptom description: There will be more abnormal noise in the engine compartment, and most people also judge that it is the abnormal noise of the engine compartment based on the sound, which is usually a metal screeching sound or a wind whistle abnormal sound; 2. Solution:

Abnormal engine noise indicates that the technical status of a certain mechanism of the engine has changed. It is mainly caused by excessive wear or even improper assembly and adjustment of some parts; 3. 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 expansion of the fault; 4. 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.

Abnormal engine noise fault phenomenon: With the increase of vehicle mileage, the original fitting clearance of engine parts will gradually loosen due to wear. When the gap is loose to a certain extent, the parts in relative motion when the engine is working will collide with each other, resulting in abnormal noise, which is the abnormal sound of the engine.

Causes of abnormal engine noise: the abnormal noise of the engine is complex and has a variety of manifestations, such as the sound of parts colliding with each other when the connecting bolts are loose; There are also abnormal noises caused by excessive friction pair clearance, poor lubrication, and ablation damage. Diagnosis and elimination of engine abnormalities or grinding noises

When examining the same bathymetric component at different locations, there will be subtle differences due to different paths of sound wave propagation. Sometimes the noise from the accessories will be transmitted to the engine, making it sound as if it is coming from the engine itself. Listen to the cylinder noise on both sides of the upper cylinder block.

Typical examples of common engine abnormal noise diagnosis are as follows: (1) Piston knocking cylinder: disassemble and adjust the cylinder clearance according to the technical specifications to eliminate the abnormal sound after the piston deviates from the cylinder.

2) Piston ring leak knocking sound: should be repaired (3) Piston embracing death: replace bearings, grind journals, troubleshoot.

4) Crankshaft bearing ring: It should be overhauled and adjusted according to the technical specifications to completely eliminate the fault. (5) Abnormal sound of the valve:

Valve clearances should be adjusted according to specifications and, if necessary, worn parts should be replaced. Abnormal engine noise fault diagnosis methods: common engine abnormal noise and fighting barrier diagnosis methods include fire cutting method, variable speed method and auscultation.

It is an effective way to judge engine failure by mastering and utilizing the law of engine squeak and squeak. If you can't judge correctly and eliminate abnormal noise in time, it will aggravate the wear and tear of parts and even cause accidental damage. Therefore, the abnormal engine noise must be repaired in time.

Engine abnormal noise has its regularity under certain conditions, and it is not difficult to master these characteristics and laws to troubleshoot. Noise is the phenomenon, failure is the essence. Listening to the noise, analyzing and judging, finding out the cause, and eliminating abnormal noises is troubleshooting.

<><Brief analysis of abnormal noise fault of vehicle engine

1: Wash the body frequently

In addition to mud, there are often sticky substances such as asphalt on the car body, which are easy to adhere to the car body and difficult to remove if it is not cleaned in time. Pay attention to the bottom and lower parts of the vehicle, where dirt accumulates the most, is more difficult to clean, and is prone to rust or damage to the paint. Don't feel that the rain washes your car clean, you don't need to wash the car, otherwise the car will "decay before it gets old".

2: Protect the paint surface

The paint surface of the car body is originally to protect the car body, and the acidic components in the rain have a corrosive effect on the paint surface, and will also cause damage to the car body over time. A simple and effective way to do this is waxing, which is low, but it doesn't last very long. Therefore, another more commonly used is the sealing glaze, which has a longer durability and is relatively higher than spontaneous combustion.

3: Sterilization in the car

The humid and hot environment in rainy days provides favorable conditions for the growth of various germs, so special attention should be paid to the hygiene and anti-bacteria in the interior of the car. In particular, it is necessary to do a good job of cleaning the sanitary dead corners of the car seat cushion and air outlet, and use special interior cleaning agents to clean and disinfect the control console, door hall and hall lift. Fortunately, on a sunny day, take out the floor mats and seat covers in the car to dry them, and naturally sterilize them at high temperatures.

4. Chassis maintenance

The automobile chassis is the carrier of many system devices on the car, and the quality of the chassis has a great impact on these systems, and the chassis in direct contact with mud and water for a long time is easy to produce rust and corrosion, so we must pay attention to the cleaning and anti-rust treatment of the automobile chassis. Chassis maintenance is generally done by a professional car repair center. The general step is to clean first, followed by anti-rust treatment, and the whole process takes about 30 to 40 minutes.

Do a chassis anti-rust treatment, the anti-rust effect can be maintained for 3 months or even longer.

<> "Troubleshooting of Abnormal Noise in Engine Work."

Abnormal noise in engine work is one of the common operation faults of automobile engines, and the causes of such faults and the methods of elimination are as follows:

1. There is abnormal sound in the engine operation.

Fault phenomenon and judgment causes, the main reasons for abnormal noise in the normal operation of the engine:

1. There is a gap between the crank connecting rod and the valve mechanism when the engine is working, especially when the speed changes;

2. It is the abnormal sound of the engine operation caused by improper adjustment or failure of the engine supply system. The method of diagnosis starts from the above two aspects.

2. Diagnostic items and elimination methods.

1. The gap between the crankshaft connecting rod journal and the bearing is too large. Determine the cylinder where the sound occurs, check the fastening of the connecting rod cover or replace the connecting rod bearing, and regrind the crankshaft if necessary.

2. The crankshaft thrust plate is worn too much, and the crankshaft swims between the shafts. Replace the thrust plate in time.

3. The gap between the main journal of the crankshaft and the bearing pad is too large, and the dull impact sound can be heard at the main bearing. Disassemble the cylinder block, overhaul the main bearing and crankshaft, and replace the main bearing if necessary.

4. Large valve clearance. The front mold adjusts the valve clearance to the specified range according to the assembly technical requirements.

5. The gap between the piston pin and the connecting rod bushing is too large, and there is a crisp impact sound on the upper part of the cylinder, which is especially obvious when the sudden change from low speed to high speed. Replace the piston pins or bushings according to the fit clearance specified in the assembly technical requirements.

6. The advance angle of oil supply is too small, the exhaust pipe is "discharged", and a low knocking sound is made in the cylinder. Adjust the oil supply advance angle according to the regulations. The oil supply angle is too far to make the engine work roughly, vibrate and vibrate, and the cylinder rhythmically emits a crisp knocking sound. Adjust the oil supply advance angle according to the regulations.

7. The gap between the piston and the cylinder liner is too large, and the cylinder emits a "dang, dang" knocking sound, which is especially obvious when the speed changes suddenly or when the low speed is under heavy load, and the sound is gradually weakened when the temperature rises. Disassemble the cylinder block and piston linkage set to check the degree of wear and tear of both, and replace the piston, piston rings or cylinder liners.

If you hear the abnormal sound of "Zizi" in the process of driving, and this is the abnormal sound caused by the problem of the engine belt, because the abnormal sound of "Zizi" is mostly the aging of the belt group of the engine, or the problem of the tensioner wheel causes the belt to be too loose, the friction abnormal sound, belt slippage, etc., such as the similar "Zizi" abnormal sound in the hidden fruit, then look for the major belt groups and tensioners inside the engine, such as the engine timing belt, generator leather imitation belt, circulating water pump belt, air conditioning belt, The problem of this abnormal noise is the abnormal sound of the engine belt, which is caused by the smooth grinding surface of the joint surface of the belt and the pulley. It usually occurs when the engine speed changes rapidly, and sometimes the belt rings when the load of the attachment driven by the belt increases. How to solve the problem of abnormal noise of engine belt 1. Check whether the accessories driven by the belt are damaged, stuck, loose or the power of the accessories has increased.

2. Replace the belt, or use 100 gauze to polish the joint surface of the pulley and the belt (light grinding is fine). 3. The temporary solution can be to drop 1 2 drops of oil on the joint surface of the belt and the pulley (will not affect the belt slippage) You have to judge that the belt is a good way is to drip oil on the belt, if the generator belt rings and the headlights are turned on more obviously, you have to take off the generator belt, turn the motor pulley, see if the generator rotates smoothly, if the generator is normal, you can check whether the battery is not stored power, because the battery storage is not good will increase the load of the generator. The above is what is going on with the abnormal noise of the engine belt and how to solve the problem of abnormal noise, I hope it will help you!

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 high-pitched and sleepy 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.

Can the engine still be turned on with abnormal noise?

When there is an abnormal noise in the engine of the vehicle, the first thing to do is to determine what causes the abnormal engine noise. After confirming that there is no danger, you can continue driving, or if it is dangerous, but you can continue driving, you can slow down and slowly drive to a nearby repair shop for maintenance.

If it is a cold start abnormal sound, it means that the engine will have a great vibration and clicking noise after a long time of stopping.

On the issue of abnormal noise of automobiles, it is difficult for ordinary car owners to distinguish which ones are abnormal noises and which ones are reasonable abnormal noises. Only nearly 20% of the vehicles that went to the repair shop to detect abnormal noises really had problems. In the case of a turbocharged engine, there is a must be a difference between the sound and the sound of a naturally aspirated engine; Models with engine guards may also make noises due to friction; After some car owners come into contact with different cars, it is likely that due to their lack of understanding of mechanical knowledge, they mistake reasonable abnormal noise as a vehicle failure.

Therefore, learn to distinguish the abnormal noise of the car and avoid wasting time and energy.

Second, the identification of car noise is limited, the sound of the car is difficult to measure with special instruments, and the sound of the car can only be described and compared with the judgment of the sound in daily life. For example, the "rattle" sound caused by the dry friction of the bearing, and the "click" sound of a small hammer hitting the cement and the floor caused by the excessive valve clearance.

1. Correctly distinguish between normal and abnormal sounds.

The vibration of each mechanism in the work of the car will emit a variety of sounds, but the sound does not mean that the car is faulty, in order to avoid unnecessary disassembly, we must first distinguish between normal sound and abnormal sound. The normal vibration sound of each system component (such as the noise on the surface of the engine), the impact sound of the gear when shifting, the air intake sound and exhaust sound of using gas as the working source, and the gear meshing noise are all normal sounds. Abnormal noise (abnormal noise) can be divided into slight noise, general noise and malignant noise according to the impact on the performance of the car.

Slight noise, such as the flashover sound of high-voltage electric leakage, the slight loose sound of rolling bearings, etc., the general volume is small, the degree of wear of the parts is not large, and there is no significant change for a long time, and this kind of fault can still maintain the normal operation of the car without repair.

3. When diagnosing abnormal noise, attention should be paid to creating good auscultation conditions and trying to eliminate the interference of other noises, so as not to affect the accuracy of judgment.

It is best to consciously amplify or reduce the sound of the sound of the sakura, that is, use a screw or other metal rod as a stestological instrument to contact the sound part to amplify the sound, or use a single cylinder fire off to reduce the sound to meet the needs of diagnosis. The auscultation site should be kept quiet to minimize human interference.