When the engine just starts, there is a knocking sound, and the sound disappears after driving for a

Hello, this situation belongs to the engine knock cylinder failure, it may be a problem with the piston ring, it is recommended to replace a set of piston rings.

When the engine just starts, there is a knocking sound, and the sound disappears after driving for a while, what is the fault? I'll answer 2 hot discussions Fights between children Should parents intervene? Anonymous user 2022-03-19 Knocking on the cylinder is an abbreviation for the fault phenomenon of the piston knocking on the cylinder wall.

This kind of failure is a malignant failure of the engine, which mostly occurs.

1. Abnormal noise of automobile air conditioning compressor.

As a high-speed rotating working part, the probability of failure of the air conditioning compressor is relatively high, and abnormal noise is a common failure.

There are many causes of compressor squeaks. For example, the compressor electromagnetic clutch is damaged, or the internal wear of the compressor is serious, etc., can produce abnormal noise.

2. The compressor electromagnetic clutch is a common part of abnormal noise.

The compressor often runs from low speed to high speed under high load, so the requirements for the electromagnetic clutch are very high, and the installation position of the electromagnetic clutch is generally close to the ground, and it will often come into contact with rain and soil, and when the bearing in the electromagnetic clutch is damaged, it will produce abnormal noise.

3. The tightness of the compressor transmission belt also directly affects the life of the electromagnetic clutch.

If the transmission belt is too loose, the electromagnetic clutch is prone to slippage; If the transmission belt is too tight, the load on the electromagnetic clutch will increase. Improper tightness of the transmission belt will cause the compressor to not work, and at worst it will cause damage to the compressor. When the transmission belt is working, if the compressor pulley and the generator pulley are not in the same plane, the life of the transmission belt or compressor will be reduced.

4. The repeated engagement of the electromagnetic clutch will also cause abnormal noise in the compressor.

For example, insufficient power generation from the generator, high pressure in the air conditioning system, or excessive engine load can cause the electromagnetic clutch to engage repeatedly.

5. The gap between the electromagnetic clutch and the compressor mounting surface.

There should be a certain gap between the compressor mounting surface of the electromagnetic clutch, if the gap is too large, then the impact will also increase, if the gap is too small, the electromagnetic clutch will work with the compressor installation surface between the motion interference, which is also a common cause of abnormal noise.

6. Reliable lubrication is required when the compressor is working.

When the compressor lacks lubricating oil, or the lubricating oil is not used properly, there will be serious abnormal noise inside the compressor, and even cause the compressor to wear and tear and scrap.

It may be that the bearing of the engine belt is broken, it is recommended to go to the repair shop to check it.

There is a chirping sound when the cold car starts, it is the sound of the belt, and the sound will disappear after a few minutes of idle warm-up! In this case, it means that the belt is aging or too loose! Just tighten it and you're good to go!

Hello, it may be that the bearing of the engine belt is broken, it is recommended to go to the repair shop to check it [There is a problem with the car, ask the car master. 4S shop professional technician, 10 minutes to solve. 】

Hello, your belt is a little bit sent to 4s o'clock to give you a tightening.

Hope it helps, I wish you a nice trip.

Hello, check the belt, and the tensioner. See if the belt is too loose [There is a problem with the car, ask the car master. 4S shop professional technician, 10 minutes to solve. 】

1.Check that the engine belt is properly tightened.

2.Inspect the engine belt pulley for damage.

If the percussion sound is larger in the upper part of the cylinder and smaller in the lower part, and then the ignition time is moved to the angle in advance, the percussion sound is aggravated, and it is proved that the fault is caused by the piston pin knocking sound. By judging the above knocking sound, the key to the engine fault can be accurately diagnosed. When encountering difficult problems, according to subjective diagnosis and objective analysis, we can find out the faults caused by various reasons of the engine, and judge the cause and effect by logical reasoning.

Common methods of analysis are:

1. Change the engine speed, gradually increase from idle speed, listen to its sound change, and then suddenly increase the throttle, and then suddenly reduce the speed to listen to the sound, judging from the sound characteristics and change laws is the knocking sound of the main bearing.

2 When the throttle is refueled, the engine shakes a lot, if the spindle pads burn or fall off, the spindle pads and journals are worn, and the radial clearance is too large, the organic oil pressure may drop before the knocking sound, and the oil gauge reading is not accurate.

3. To determine which bearing is ringing, it should be judged according to the sound location, and a suspicious bearing should be tested off from the fire near the two cylinders, if the sound is weakened, the bearing will sound.

4. Open the oil port cap of the adder, listen to whether the sound is more obvious, and then use the screwdriver to short-circuit the spark plug for short circuit test, if the sound decreases or disappears, if the screwdriver is suddenly removed, it will make a "dang" sound, which proves that the bearing sounds.

5 If both cylinders make a sound, a single cylinder short circuit test should be carried out, if the sound of both cylinders short circuit disappears, it proves that the bearings of both cylinders are sound.

6. The lining alloy is burned, the radial clearance is too large, it can be tested by the method of short circuit inspection, the sound is not reduced during the test, on the contrary, it increases with the engine shaking sound, when the oil channel is blocked and burns the bearing, the sound becomes a dry friction sound similar to the oil pan, which is very clear.

7 Pour a small amount of oil into the suspicious cylinder, wait for a while, and then start the engine, if the knocking sound is reduced or eliminated, and the knocking sound is repeated after a while, it is the cylinder sound.

8. Test the collision sound between the piston top and the cylinder gasket, if it cannot be checked by the fire-off method, you can touch the head of the screwdriver on the cylinder wall cover, if you can hear a large vibration there, it means that the sound of the cylinder exists.

9. Test by short-circuit fire breaking method, if the sound is reduced, but can not be eliminated, put the screwdriver on the spark plug, pay attention to observe and listen to the sound, if the piston ring is broken, it will make a "boom, boom" sound; If the piston ring collides with the cylinder shoulder ring, you can touch the screwdriver to the cylinder head and feel a noticeable vibration.

10. Check the spark plug pin knocking sound, first open the oil port cap, listen to whether the sound disappears or weakens with your ears, when the fire is refired, it makes a "click" sound, and then immediately resumes the original knocking sound, indicating that the cylinder has a sound.

The abnormal sound of the engine has the sound of clattering iron, which is caused by the engine knocking on the cylinder. There are many reasons for knocking a cylinder, engine knocking can lead to knocking on the cylinder, and severe wear on the cylinder wall can also lead to knocking. After this happens, it is more common to go to a professional institution or 4S shop to find a professional technician to diagnose the cause of the failure, and then repair the engine cylinder knocking caused by the knocking.

Detonation is an abnormal combustion phenomenon in the engine. Detonation occurs in the compression stroke. When the engine is in the compression stroke, the intake and exhaust valves of the engine are closed, and the engine's pistons run upwards.

The piston can compress the combustible mixture when it runs upwards. The compressed combustible mixture increases in pressure and temperature, and if the combustible mixture burns ahead of time, this is a knocking. The combustible mixture pushes down the piston, which is running upwards at this point.

This affects the engine's power output and fuel economy. Severe knocking can even cause the engine to deform the connecting rod or the piston to burst. Most engine knocks are caused by improper gasoline or a lot of carbon deposits in the combustion chamber.

It is recommended that you choose the correct number of gasoline for your car when you usually use the car, and also go to the gas station with better oil quality to refuel. Don't be greedy for cheap and go to a gas station with poor oil quality to refuel.

The temperature is too high to deform the piston, causing a knocking sound.

The engine knocks, causing a knocking sound (damage to the knock sensor).

The engine ignition was premature, resulting in detonation.

The engine makes a knocking sound is an abnormal fault, and the direct phenomenon is to pull the cylinder, and the common reasons for the failure are:

1. The amount of engine lubricating oil is reduced, which causes the cylinder liner and piston group to wear and pull the cylinder;

2. The engine cooling system components work poorly or are damaged, resulting in high engine temperature, which makes the piston stick to the cylinder and pull the cylinder;

3. The engine runs overload for a long time;

4. The supporting quality of engine 6 is not good;

5. The engine lubricating oil specification does not match the specified model of the engine;

6. The quality of the lubricating oil used in the engine is not good;

7. Oil consumption increases due to turbocharging damage;

8. Reasons for maintenance and assembly level, etc.

When the cold car starts, the engine has a lubrication and exhaust pass; Maybe the du you hear is the sound of the engine exhausting. Don't worry, you can open the cabin cover when the cold car starts to listen to it and confirm whether it is the sound of engine exhaust. When the engine is fully lubricated, the sound can be eliminated; It is recommended that you let the engine lubricate after the cold start, and wait for the idle speed to drop before driving.

Under normal circumstances, it is not a problem with the engine, it is generally fine in summer, but this situation is more obvious in winter. When the engine is just started, the various fluids are not fully lubricated, and a certain sound will be emitted, and at the same time, the belt will also make a certain sound. These are all normal.

Hello, according to your description, the preliminary judgment should be the abnormal sound of the belt, it is recommended to go to the repair station to test, I hope to help you.

Hello, when it is just started, the hood opens to see if it is the sound of the belt??? You said that the phenomenon is very consistent with the abnormal noise of the belt!!

Hello car owner, this needs to check whether the belt is loose. If it is loosened, it will be fine, if it is not loose, it may be aging.

Hello, it should be the belt that is loose.

This situation may be caused by the starter motor not quitting work in time, and it is enough to replace it with a new one.

It may be the abnormal sound caused by low oil pressure or the wear of the hydraulic tappet itself, and then the abnormal sound caused by the continuous accumulation of oil sludge and carbon deposits on the throttle.

This situation may be caused by damage to the engine damping block, and only a new one needs to be installed to solve the abnormal noise.

Summary. Hello dear! I understand your feelings very well.

The engine fault light is not on, and there is a knocking sound when the engine is idling, and the continuous metal knocking sound can be heard. The sound is loud when the temperature is low, and the sound decreases or disappears when the temperature rises. Cause of failure:

1. The wear gap between the piston and the cylinder wall is too large. 2. The connecting rod is bent. 3. The piston is deformed due to its over-tight pin assembly.

4. The connecting rod bearing is assembled too tightly. <>

The engine fault light is not on, and there is a knocking sound on the fire.

Hello dear! Explain your feelings. The engine fault light is not on, and there is a knocking sound when the engine is idling, and the continuous metal knocking sound can be heard.

The sound is loud when the temperature is low, and the sound decreases or disappears when the temperature rises. Causes of failure: 1. The wear gap between the piston and the cylinder wall is too large.

2. The connecting rod is bent. 3. The piston is deformed due to its over-tight pin assembly. 4. The connecting rod bearing is assembled too tightly.

Exclusion method: 1. When the engine is lifted at a low standby speed, the fire test is gradually broken, and the sound is weakened or disappeared after the fire is broken, which is the sound of the cylinder. 2. When idling, the sound of knocking on the cylinder is obvious and clear; As the engine temperature rises or revs above medium speed, the sound decreases or disappears.

3. Remove the spark plug, add a small amount of concentrated lubricating oil to the cylinder from the spark plug hole, after the lubricating oil is injected, use the starter to drive the crankshaft to rotate several times, so that the gap between the piston and the cylinder wall is filled with lubricating oil film, and then start the engine, if the sound is significantly weakened or disappeared in the moment after starting the slippery auspicious, but with the loss or ablation of the oil film, the sound appears quickly, which can prove that the cylinder knocks on the cylinder.

Hot car idling only appears.

This sound may be the sound of the valve, the cool car will continue to idle for a period of time after starting, during this period of time, the air will be lifted by Qi Ant to the idle speed is too high, and the sound will be much smaller after the idle speed is lowered. It's okay in this case!

No, do you have this sound when you are cold in the car!

The main reasons for the phenomenon of the engine of the car shaking, unstable idling, inability to refuel, abnormal sound, and engine failure to start are as follows: 1. The battery voltage of the car is low; Specific detection method: test the battery voltage with a three-purpose meter voltage level, if it is below 10V, it is recommended to replace it.

If it is around 11V, it is barely used; Be prepared for replacement. Above 12v can be used, but other reasons need to be found; 2. Check whether it is caused by carbon deposits; If you travel about 20,000 km, focus on checking and cleaning the throttle; 3. Inspect, test and replace spark plugs;

4. Confirm the quality of the gasoline added;

5. Detecting the ignition switch; 6. Test and detect the starter, gasoline pump, sensor and other related components of the starting and oil supply system; 7. After powering on, do not start immediately, wait for 30 seconds to 1 minute, and then ignite; See if it works; Regardless of any of the above situations, pay attention to the time when the car cannot be hit once, be sure to play again after an interval of 15-30 seconds to protect the battery but not generate power and prolong its service life.