What is the reason for the engine shaking and loud noise after the car is turned off?

Possible causes of engine shake are:

Blocked air cleaner causes idle speed to be too low.

A cylinder does not work or works poorly.

The oil pump is not in good condition, and the oil pressure is unstable.

Carbon deposits in the combustion chamber.

Carbon accumulation in the grease nozzle and uneven fuel injection.

The cylinder is worn, and there is air leakage.

The valve is not closed tightly.

The idle speed is low. The high-voltage line is broken.

The water temperature is abnormal, and the feedback of the temperature control switch is not accurate.

Occasionally, if the cylinder is missing, the fault light will not be lit.

In the event of a recurrent fault, the engine EPC light will give an alarm.

Engine shake is considered to be due to two reasons:

1. Throttle.

If the fuel injector is too dirty, it will shake if there is too much carbon.

After a certain mileage of the car, the throttle valve is too dirty, which can cause the throttle to close poorly or idle.

The stuckness of the stepper motor can cause the engine idle speed to be too high, and the carbon deposits generated by the engine in the working process will also cause the vehicle to shake, especially when starting the vehicle, the engine will shake more than normal, and even sometimes there will be a phenomenon that can not be started at one time.

When a vehicle shakes out, the throttle and fuel injector should be checked first. If you find that the throttle valve is too dirty or the fuel injector has too much carbon deposit, it should be cleaned in time.

2. The aging of the engine mat will also cause shaking.

Car shake is also sometimes related to the aging of the engine feet, which are actually the shock absorption system of the engine, which is responsible for absorbing the subtle vibrations of the engine when it is running, and if there is a problem with the engine feet, these vibrations will be transmitted to the steering wheel.

In the cab, jitter occurs when idling.

Engine Maintenance Precautions:

1. Clean the air filter.

The air filter is directly related to the air intake of the engine during the driving of the car.

The manager of the dealership told reporters that the vehicle is only driving in the city, and the air filter will not be blocked, but if the car is driving on a dusty road, it needs to pay special attention to the cleaning of the air filter.

2. Remove throttle sludge.

There are many reasons for the formation of sludge at the throttle, some of which are the formation of carbon deposits at the throttle by the exhaust gas of fuel combustion; Then there are the impurities that are not filtered by the air filter and remain at the throttle. The increase in oil sludge will cause air resistance, which will lead to an increase in fuel consumption.

3. Clean the fuel injector for carbon deposit.

Because the combustion chamber is prone to carbon deposits, which can lead to difficulties in start-up; Carbon deposition at the fuel injector will also lead to oil channel blockage, gasoline injection deformation, poor atomization, and fuel consumption will naturally increase.

The cold start of the car and the stalling or shaking are the causes of carbon deposits.

There are these points when the cool car starts to shake: 1. The throttle is dirty. When the cool car starts, the engine intake is insufficient, resulting in insufficient combustion, and after a few seconds, the computer adjusts itself, and it is fine.

2. The carbon deposition of the intake valve is serious. The oil sprayed by the cool car is sprayed to the intake valve, and most of the carbon deposits are adsorbed by the valve, causing the fuel in the cylinder to be too thin, and then it will shake a few times. Both are very common.

The solution is to clean. For the first problem, 4S cleans the throttle and intake tract, and for the second problem, uses high-grade fuel additives to clean the intake valve carbon deposits. This can basically be solved.

Cold car shake is actually a cylinder that is not working well, and has nothing to do with the water temperature sensor.

The engine runs for 1 minute, touch each spark plug dimension with your hands, find out the one with the lowest temperature and the one with the highest temperature, and observe the color of the two spark plug discharge electrodes, the dark yellow one should be the one that burns a lot, and the one with a black surface (the one that burns well and is hot) should be the one that burns badly (the one that burns badly and is not hot) and adjusts the discharge gap of the non-hot one according to the hot one.

The difference between the unstable operation of a cold car and the good operation of a hot car is whether the concentration of the mixture and the ignition intensity are appropriate, resulting in instability.

Analysis of the causes of car shake:

1. Cold start jitter.

First of all, starting from the cold start, the main reason for the cold start body shaking is that the fuel combustion is insufficient, resulting in insufficient power of the car. The ignition energy is low, and when starting, especially when the temperature of the fuel and lubricating oil is low, more oil is required to meet the power. Over time, the pole gap of the spark plug gradually increases, resulting in a decrease in ignition energy and poor fuel atomization, which leads to the shaking of the body.

In addition, the ignition energy can also be reduced due to the aging of the ignition coil, the aging of the high-voltage wire of the spark plug, or the leakage of electricity.

2. Suspension system problems.

Body shake is also related to the aging of the suspension system. It is mainly responsible for filtering out the shake of the engine when it is running, and if there is a problem with the suspension, these vibrations will be transmitted directly to the steering wheel and cab, affecting the driving. When the engine is idling, it is easy to cause shaking when the electrical system in the car is turned on.

The engine will increase the load when the electrical appliances are turned on, causing the idle speed to drop, and to compensate for the jitter caused by the idle slip, the engine will automatically increase the speed by partially. So, when the electrical system, especially the air conditioner, is turned on, the engine will often shake. This jitter is likely to be caused by the aging of the shock absorber and needs to be replaced in time.

3. Tire problems.

For tires, the tire must be balanced once when the car is replaced with new tires and new steel rims, otherwise the steering wheel will be prone to shake when the counterweight is uneven. If you find that the tire weight is not equal, you need to add lead to the inside of the rim to average the weight of the tires on both sides. Whether it is a general steel ring or a lightweight aluminum ring, it may deform or crack when subjected to a certain external force.

Deformation of the rim can cause shaking when driving, uneven weight of the rim can also cause shaking when driving, and incorrect angle of the rim can also cause shaking when driving.

4. Throttle problems.

The most common cause of car shake may be a dirty throttle valve and excessive carbon build-up in the fuel injector. After the car travels for a period of kilometers, the throttle valve will be too dirty to cause the throttle to close loosely or the idle motor to stagnate, resulting in the engine idling speed is too high, and the carbon deposits generated by the engine in this process will also cause the vehicle to shake, especially when starting the vehicle, the engine will shake more than normal, and even sometimes there will be a phenomenon that can not be started at one time. Therefore, when the body shakes, the first thing to do is to check the throttle and fuel injectors.

If you find that the throttle valve is too dirty or the fuel injector has too much carbon deposit, you should clean it with fuel injector cleaner or throttle cleaner in time.

5. The oil pressure is unstable.

If you still find that the body shakes after these are finished, it is recommended that you go to the repair shop to check whether the fuel supply pressure and intake pressure sensor are normal, if the oil pump supply pressure is not normal, the intake pressure sensor is wrong and improper work will cause the body to shake.

The reason why the cold car shakes when it starts, and after a while it will be normal:

1. Low temperature: it is necessary to check the carbon deposition of the spark plug and clean it, whether the electrode gap meets the requirements, and replace the spark plug if necessary;

2. The concentration of the mixture is too thin or too thick: it is necessary to check whether the oxygen sensor is damaged;

3. Carbon deposition in the air intake system or oil circuit system: PNF fuel cleaner can be used to clean the places that are easy to form carbon deposition;

4. Water temperature sensor failure: you need to check the water temperature sensor, you can soak the water temperature sensor in warm water, and then measure the change of its resistance value, if there is no change, it means that it has been damaged, and it can be replaced.

Specific solutions to idle jitter:

1. The engine has serious carbon deposits. The most common cause of idle judder is excessive carbon build-up on the throttle or injector. When there is too much carbon deposit inside the engine, the gasoline sprayed by the fuel injector during cold start will be absorbed by the carbon deposit, resulting in a mixture that is too thin and making it difficult to start.

After landing, the gasoline adsorbed on the carbon deposits will be sucked into the cylinder by the engine and burned, which will thicken the mixture. The mixture is sometimes dilute and sometimes thick, which will cause idle jitter after cold start. The lower the temperature, the greater the amount of oil required for cold starts, and the more the presence of carbon deposits affects cold starts.

The solution is to clean the carbon deposits at the throttle and injector.

2. Poor ignition system and poor ignition of spark plugs will also lead to engine idling and shaking. If there is a problem, check if the ignition system is faulty and if there is too much carbon deposited in the spark plug.

3. The oil pressure is unstable. If you have cleaned the engine carbon deposits, cleaned the throttle valve or replaced the spark plug, and there is still the problem of body shaking when idling, it is recommended to go to the 4S shop to check whether the fuel supply pressure and intake pressure sensor are normal. If the oil pump supply pressure is not normal or the intake pressure sensor is incorrect, it can also cause the body to shake when idling.

Solution; The best way is to clean the oil circuit, clean it regularly, there is no specific experience in the research and development parameters of the clean engine from the new car, coupled with the continuous improvement of emission standards, can not adapt to the change of fuel, all manufacturers of the engine are unable to solve this jitter problem in the short term, plus the fuel quality is not very good or the initial fuel of the new car factory is stored for too long, resulting in a rapid increase in the colloidal composition of the oil circuit, which will continue to pollute the fresh fuel and cause no good fuel to participate in combustion in the later stage. The occurrence of excessive carbon deposits is especially common for China VI vehicles. We can only gradually alleviate most of the problems by maintaining clean oil circuits. The use of PNF dope fuel additives can solve the problems caused by carbon deposition.

The fault of starting jitter and ignition zd focuses on checking the gasoline pump, which needs to measure the fuel pressure, and the gasoline pump can not maintain the normal oil pressure, which will lead to unstable idle speed after the cold car starts, or the fault of stalling.

Check the carbon deposits in the throttle body, idle speed valve, fuel injector and air intake tract while driving, as excessive carbon deposits will cause the vehicle to idle unsteadily or stall while driving. Secondly, it is important to check the crankshaft position sensor, camshaft position sensor, ignition coil and gasoline pump, which can also cause the vehicle to stall while driving.

What is the reason why the engine shakes so badly when the car starts and stalls? Fault lights do not turn on regularly should not be a problem with accessories, focus on detecting combustion problems, if there are many times of fire in the data flow, then it is not good to burn, this kind of combustion is not good for a long time to produce carbon deposits, as long as the fuel tank is added to the idle jitter special fuel additives and the national VI standard fuel additives - Si Youpu fuel additives fuel additives additives can be cleaned, you can also understand in this way, the underground fuel tank of the gas station is cleaned once in February, the car fuel tank is not so well sealed, and it is natural to clean it regularly. I am using the idle jitter special fuel additives and the national VI standard fuel additives - Si Youpu fuel additives fuel additives before the idle jitter becomes smooth.

There are several possibilities for engine shake.

1."The air filter is dirty, clogged, and not replaced in time, or the high-voltage line is broken and affects the ignition and causes the engine to shake.

2.Engine shake caused by spark plugs not being replaced in time or low fuel pressure.

3.Dirty throttle valves, clogged injectors, or low cylinder pressure can cause engine jolting.

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.

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.

Lack of motivation problem.

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

1.Engine knocking. It is a sound similar to metal percussion, which can also be said to be a knocking cylinder, and the cause of failure can be divided into three types:

a. The fuel is unqualified, and the inferior fuel or the fuel with too low grade is used. b. Engine timing control error, such as ignition advance angle is too large, etc., readjust the timing. c. Too much carbon deposition inside the engine.

2.Abnormal valve noise. After the car, the engine "clicks", which is the sound of the valve, especially after the cool car lands, because the oil pressure has not gone up at this time, and the valve has not been lubricated in place, so it will be fine after a while.

This can be the case if your car is parked for a long time. If this sound keeps ringing.

What is the reason why the engine shakes when the car starts, it is terrible, and it stalls? In this case, you should drive the car to the four-S shop, because the engine is likely to have serious carbon deposits in the gasoline cylinder where the engine works, or it is blocked.