After the car started and walked for about 15 minutes, then the cylinder was knocked and then the en

When the gap between the piston and the cylinder is too large due to serious wear, the piston is affected by the side pressure in the compression stroke, that is, the force of the connecting rod to the piston along the horizontal direction, and the direction of action of the side pressure or horizontal component changes when the piston passes the top dead center, and when the piston is instantaneously reversed, it quickly changes from one side of the cylinder wall to the other side, and the cylinder wall collides and produces a sound, looking back from the front end of the engine, if the direction of rotation of the engine crankshaft is clockwise, Then this sound starts between the left cylinder wall and the piston of the engine at the beginning of the piston power stroke, and is in the middle and upper position of the cylinder wall.

Reasons: (1) The gap between the piston and the cylinder is too large.

2) The piston direction is reversed or the piston is deformed.

3) Poor lubrication of the cylinder wall.

4) The connecting rod is bent or twisted and deformed.

5) Blockage of lubricating oil channels.

6) Serious carbon deposition in the combustion chamber.

7) The injection advance angle is too large.

8) The combustion rate of combustible mixture is too fast.

Hello, there may be a lack of cylinder, go overhaul, if my answer is helpful to you, please set it to! Thank you!

It is recommended that you go to the repair shop It should be the wrong oil [car questions, ask the car master. 4S shop professional technician, 10 minutes to solve. 】

Hello, for this situation, it is very likely that the engine's oil supply system is faulty, this must go to the repair shop for a comprehensive inspection, generally need to test the oil pressure, check the ignition system.

1. For novices, turning off halfway is not a new topic, and the main elimination method is to improve their driving skills after rapid running-in.

2. Use high-standard, high-quality and qualified fuel.

3. Clean the oil circuit thoroughly, including fuel injectors, throttle valves, fuel tanks, etc. It may be that the quality of the oil you add is not up to standard, there is too much grease, the oil path is blocked, and the oil attack is not smooth.

Pedal clutch problem.

Novices do not control the clutch well, and it is easy to raise the clutch too quickly and the vehicle accidentally stalls when driving. Therefore, when starting with a manual transmission car, the clutch should be well controlled and the left foot should be steady. Although automatic transmission cars rarely stall, if the clutch is lifted too quickly, it will also stall.

2 4 brake problems.

Many novices drive manual transmission cars, and when braking, especially when braking suddenly, they often forget to step on the clutch at the same time, which will suffocate the car and turn off. So when braking, either take neutral or press the brakes and press the clutch at the same time. 3/4

The problem of lack of fuel in the car.

4 4 Lack of power problem.

If there is a serious lack of power while driving, it will also cause stalling.

1. Circuit failure: This may be due to low-voltage power failure and flameout during driving.

2. Electrical device failure: This problem is generally the ignition coil, capacitive electrical unit, and electronic ignition module. It can start at the beginning, and then it will go out after a while, and then it can start again, and it will go out again.

3. Oil circuit failure: the gasoline pump is damaged, the oil pipe is broken, the oil inlet of the vaporizer is blocked, and the fuel tank is out of oil.

4. Sensor failure: throttle position sensor, intake flow sensor, intake pressure sensor, crankshaft position sensor, camshaft position sensor failure and other faults.

Precautions for driving the car.

In order to ensure the safety of the battery pack while the vehicle is driving, the car company will provide a protective frame for the battery pack, also known as the battery module frame. At present, most new energy vehicle battery packs are arranged on the chassis, which is easier to contact with water during driving, so the protection frame will carry out special insulation protection for the high-voltage part of the battery pack to protect the safety impact that external forces such as wading and collision may cause to the battery pack.

In order to test the waterproof performance of the battery pack, they soak the battery pack in water for 24 hours, and then test the performance of the battery to ensure that the external water will not enter the battery and cause a short circuit.

Hello! Check the water temperature sensor to see if something is wrong.

Reasons why the engine stalls after a few minutes of starting:1. Trigger the car anti-theft system. Trigger the car anti-theft system, lock the engine, so that the engine can start, but can not run, release the key protrusion one or two to turn off, and the anti-theft light is on.

2. The ignition switch is faulty. There is electricity on the ignition line when starting, and when you release the key, the power will be cut off, and the ignition will suddenly turn off.

3. The ignition module is damaged or the ignition reference signal line from the ignition module to the engine computer is damaged.

To put it simply, when the engine speed is lower than 500r min at the initial stage of starting, the ignition module is controlled by the ignition module according to the crankshaft and camshaft position sensor signal and its internal inherent data, and when the engine speed is higher than 500r min after starting, the ignition control and fuel injection control are transferred to the engine computer, and the engine computer Xiaotong cover is comprehensively controlled according to the ignition reference signal sent by various sensor signals and ignition reference signals sent by the ignition module.

The reasons for the knocking of the cylinder when the car starts: it is generally caused by the following situations:

1.Ignition is too early.

2.Bad knock sensor.

Poor system. 4.The spark plug model is not the right or the gap is too large, the occult value of the gasoline used is too low, the combustion chamber is seriously decarbonized, and the engine temperature is too high, 5The gap between the piston and the cylinder wall is too large, and the lubrication conditions of the cylinder wall are poor.

How to judge the piston knocking cylinder:

1.Cylinder-by-cylinder oil cut-off. Take the method of cutting off the oil cylinder one by one to determine the position of the cylinder, if the oil is cut off to a certain cylinder, the sound is significantly reduced or disappears, and when the oil supply is resumed, the obvious "click" sound can be heard, indicating that the cylinder piston knocks the cylinder.

2.In order to further confirm that the cylinder piston knocks the cylinder, you can remove the injector of the cylinder, add a small amount of CD grade supercharger oil to the cylinder (play a sealing role), and then install the injector, start the engine, the knocking sound disappears or weakens, and the knocking sound appears again after a while, which is the piston knocking on the cylinder.

The main reasons for the knocking of the piston cylinder in production are as follows:

1.The gap between the piston and the cylinder wall is too large. The standard clearance between the piston skirt and cylinder of the WD615 series engine is 0 143-0 182, and the maximum wear limit is 0 35-0 40.

2.After the engine runs for a period of time, the cylinder piston is worn, coupled with poor lubrication, the matching gap between the piston and the cylinder increases due to wear, and there is a more serious step at the lower part of the first air ring, so that the piston strikes the cylinder and makes an abnormal sound.

3.After a period of operation, the piston skirt and cylinder are seriously worn, resulting in serious derounding and knocking of the cylinder.

4.Individual connecting rods are deformed due to various reasons, resulting in piston eccentricity, and the gap becomes larger and the cylinder is knocked. Piston knocking on the cylinder will lead to high engine fuel consumption, engine oil channeling, high fuel consumption, and poor economy.

When the piston knocks the cylinder seriously, it will also crush the piston and damage the cylinder, so that the connecting rod will break and the cylinder block will be damaged.

When encountering piston knocking cylinders, the following methods can be used:

1.After the engine starts, there is a knocking sound when running at low temperature, and after the temperature is normal, the sound disappears, and it can be temporarily disposed of and continue to run.

2.When the engine temperature is normal, there is an obvious knocking sound, try to avoid high-speed operation, and disassemble and repair as soon as possible.

3.After removing the cylinder head and pulling out the piston, it is found that the cylinder is seriously out of round, strained, or the gap between the piston and the cylinder is too large, it should be replaced, and the cylinder liner, piston and piston ring should be replaced.

4.If the connecting rod is found to be deformed, it should be replaced as much as possible.

One is the drag gear, the other is the ignition time early, and the other is the hardware problem, the plug knocking sound is a crisp and rhythmic metal hitting sound consistent with the number of work.

1) Fault phenomenon.

l) When the engine is idling, a crisp knocking sound is found in the upper part of the cylinder, like a hammer tapping on the concrete floor (very similar).

2) The sound is obvious when the car is cold, and the sound is weakened or disappeared when the car is hot.

3) After the cylinder is "fired", the sound is weakened or disappears.

2) Causes.

1) The gap between the piston and the cylinder wall is too large.

2) Poor lubrication of the cylinder wall.

3) Check and judge. Listen to the engine and the oil port, the sound is obvious when idling, use the screw plug to tie the iron, listen to the cylinder by cylinder, identify which cylinder the sound is generated, or inject a small amount of oil into the cylinder, install the spark plug, start the engine, if the sound weakens or disappears, and then appears after a while, it can be judged that the cylinder knocks on the cylinder.

If there is still an obvious knocking sound after the engine working temperature is normal, the cause should be identified in time to be eliminated.

There are many situations of knocking cylinders, some are design problems, the piston skirt is not well designed, the temperature rises, there will be thermal deformation, resulting in knocking cylinders, or gasoline in the cylinder deflagration or surface ignition will also produce knocking cylinders.

Operation problem The throttle is bigger, the clutch control is better, if it is not the reason for the operation, the engine will have to be repaired

Do you feel like your car's tires are vibrating? Mine too.

The phenomenon that the cold start knock cylinder will disappear after a while belongs to the cold start knock cylinder of the engine. It is characterized by a rhythmic metal knocking sound when the upper part of the engine is idle after a cold start, and this sound disappears after adding a little throttle, and weakens or disappears when the engine temperature rises. This phenomenon is especially noticeable in the cold winters, especially in diesel engines, which almost all have such a sound.

The main reason for this phenomenon is that the piston and the cylinder wall are poorly lubricated when the wide motor is coldly started, or the gap between the piston and the cylinder wall is too large, or the cylinder of the piston is too large, which causes the piston to swing in the cylinder under the action of high-pressure gas pressure instantly, knocking on the cylinder wall, and producing a metal knocking sound. In addition, the material of the piston and cylinder block also has an effect on this sound. If they are made of the same material, such as aluminum alloy or cast iron, the sound is relatively low or not present on the base.

If the piston is aluminum alloy and the cylinder block is cast iron, this sound is more common. We have a diesel engineering truck here. The original car is a cast iron piston, and the cylinder is basically free of cold knocking.

Later, after the mechanical fault was repaired, the aluminum alloy piston was replaced, and the cold knock on the cylinder became very obvious, which is the material factor.

Generally speaking, this situation rarely happens in the cold start state of a new car. If such a phenomenon occurs after the engine is aging, it means that the internal parts of the engine are aging, and the piston and cylinder wall mating clearance is large, which will lead to loud noise.

Millions of car purchase subsidies.

The phenomenon of cold car starting cylinder knocking will disappear after a strong time belongs to the engine cold car cylinder knocking sound, which is characterized by the rhythmic metal knocking sound of the upper half of the engine starting at idle speed when the engine starts, and there is no sound when the throttle is added a little, and the sound will be weakened or disappeared after the engine temperature rises. This phenomenon is especially obvious in the cold winter, especially for diesel engines, which almost all have such a sound.

The main reason for this phenomenon is that the engine is poorly lubricated between the piston and the cylinder wall when the cold car starts, or the matching gap between the piston and the cylinder wall is too large, or the cylinder of the piston is too large, resulting in the moment of work, the piston is subjected to the action of high-pressure gas pressure, swings in the cylinder and knocks on the cylinder wall, causing the sound of metal knocking. In addition, the material of the piston and cylinder block will also have an impact on the sound, if the two are of the same material, such as aluminum alloy or cast iron, the sound is relatively small or basically none; If the piston is made of aluminum alloy and the cylinder block is cast iron, this sound is more common. We have a diesel engineering vehicle here, the original car is a cast iron piston, basically there is no cold car knocking cylinder sound, and later after the mechanical failure overhaul was replaced by an aluminum alloy piston, the cold car knocking cylinder sound Li Shansheng became very obvious, this is the factor of materials.

Generally speaking, the new car will rarely appear in the state of cold start, if there is such a phenomenon after the engine aging, it means that the parts inside the engine have been aged, and the matching gap between the piston and the cylinder wall is large, and the noise will be larger than the collapse.

Photo by Lin Hong) @2019