What s wrong with my BMW shaking at low speed in corners?

There are several causes of idle jitter:

1.The engine has a lot of carbon deposits.

The most common cause of car shake is a dirty throttle or excessive carbon build-up in the fuel injector. When the carbon deposition inside the engine is excessive, the gasoline sprayed by the cold start fuel injector will be absorbed by the carbon deposition in large quantities, resulting in the mixture of cold start being too thin, making it difficult to start, in this case, only when the gasoline absorbed by carbon deposition is saturated, it is easy to get on the car, and the gasoline adsorbed on the carbon deposition after the car will be sucked into the cylinder by the vacuum suction of the engine for combustion, and the mixture becomes thick, and the combustible mixture of the engine is dilute and thick, causing idle shaking after cold start. The lower the temperature, the greater the amount of oil required for the cold start, and the more carbon deposits will affect the smooth cold start.

Solution: Clean the oil circuit and check whether the idle motor has carbon deposits and should be cleaned.

2.Problems with the ignition system.

Check the working condition of the spark plug, high-voltage wire and ignition coil, the ignition system is not working well, and the spark plug tripping condition is not good, which will also lead to this kind of failure.

Solution: Check whether the spark plug has too much carbon deposit, and replace the spark plug.

3.The oil pressure is unstable.

If you have cleaned the engine carbon deposit, washed the throttle, changed the oil pad and spark plug, etc., and still found that the body shakes when idling, it is recommended that you 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 abnormal or the intake pressure sensor value is wrong and the work is not good, the body shake will be triggered.

Solution: Check the oil pressure and replace the parts if necessary.

4. Aging of engine parts.

Car jitter is also related to the aging of the engine feet (also known as claw pads). The engine foot is actually the suspension system of the engine, and the engine foot is responsible for absorbing the subtle shake of the engine when it is running, and if there is a problem with the engine foot, these vibrations will be transmitted to the steering wheel and cab, causing shaking when idling.

Workaround: Replace the parts. Thank you!

Why does your BMW shake a lot when cornering at low speeds? The spring suspension is stiffer. In addition, if the hormone is single-handed, it is because the weather is particularly cold.

1. The positioning angle of the front wheel is out of alignment, and the toe is toe.

excessively large; 2. The air pressure of the front forum is too low or the tire is unbalanced due to repair and other reasons;

3. The front spokes are deformed or the number of tire screws is different;

4. The installation of transmission system parts is loose;

5. a transmission shaft.

bending, dynamic unbalance, deformation of the front axle;

6. The shock absorber fails, the stiffness of the front leaf spring is inconsistent, and the frame is deformed.

Diagnosis and elimination of high-speed vibrations:

1. There are two situations of high-speed vibration, one is that the vibration is strong with the increase of vehicle speed, and the other is that the vibration occurs during a certain higher speed period, which causes the steering wheel.

Dithering. When judging, the drive axle is erected first, the front wheel is plugged with a safety plug block, the engine is started and the high-speed gear is gradually shifted, and the driving wheel reaches the final test vibration speed. If both the body and steering wheel shake at this time, it is caused by vibrations caused by the drivetrain.

Because Xunji is in a stationary state at this time, if the final vibration speed is reached, the car does not shake, the cause of vibration is the fault of the front axle part of the car;

2. Check whether the positioning angle of the front wheel and the front wheel meet the requirements, and if it is inaccurate, it should be adjusted;

3. Set up the front axle to test the wheels, check the static balance of the wheels and whether the tires are too deformed. If necessary, a good wheel can be changed for comparative experiments.

The owner of the building prepares the beams, cleans the valves, removes carbon deposits, checks the spark plugs, inspects the high-pressure envelope, inspects the crack fuel pump, and inspects the oil products.

Each of the above items is the root cause of engine shake, check them one by one.

The second cause of car shaking - idle jitter - idle motor Jitter at idle is not only a problem with the engine's suspension system (engine feet), but also a problem with the operation of the engine itself. Poor engine operation can be divided into oil, electricity, air three reasons, the most likely to affect the idle shake cause, is the idle motor failure problem...

The most fundamental reason for the shaking phenomenon of unstable car idling is poor combustion in the cylinder. If the combustion is not good, the power provided by the car will not be enough, and the car will shake.

Throttle oil and throttle carbon deposits, dirty intakes, blocked intakes can cause idle pulling, throttle carbon deposits or oil are the most common causes of unstable idling.

Spark Plug Failure: Weak sparks caused by individual spark plug failures can also cause carbon deposits, which can be cleaned to restore spark plug activity, but some spark plugs have a fast lifespan and can reduce performance.

Blocked oil circuits: There are also oil circuit blockages and intake pipe failures represented by fuel injectors. When the oil circuit represented by the injector is blocked, the fuel supply pressure is insufficient, the fuel atomization is poor, the mixing ratio is unbalanced, and the combustion is incomplete, which leads to related failures.

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 the car hits the car, the gasoline adsorbed on the carbon deposits will be sucked into the cylinder by the engine and burned, and the mixture will be thickened by the wide bend. 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, regular cleaning, from the new car to clean the engine R & D parameters have no specific experience, 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 new car factory initial fuel storage for too long, resulting in a rapid increase in the colloidal composition of the oil circuit, will be envious of the continuous pollution of fresh fuel, resulting in no good fuel can 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 following is an introduction to the possible causes of BMW car shaking: 1. Engine cylinder shortage: Engine cylinder deficiency mainly refers to the engine has one or more cylinders that are not working normally, which is mostly related to ignition coil failure.

2. Aging or loosening of the foot glue: The function of the foot glue is to reduce the vibration and buffer when the imitation Hengxian machine is working, and to fix the engine. Once these feet are aged or loosened, the shaking will become extremely serious.

3. Carbon deposition problems: carbon deposition problems include cylinder carbon deposition, throttle carbon deposition, spark plug carbon deposition, intake carbon deposition, etc., when the carbon deposition is excessive, the ignition energy of the car, the amount of stopping, the intake efficiency, and the mixture ratio will be affected, resulting in the unstable power output of the car, and the phenomenon of shaking will occur at idle speed and acceleration. 4. Fuel system failure:

The addition of inappropriate fuel labels leads to a decrease in the output power of the car, and a decrease in power; Or due to the blockage of the vent hole of the fuel tank cap or the partial blockage of the oil pipe, the backup shot of the required oil volume cannot be satisfied**.

The reasons why BMW started jitter broadband are as follows:

The engine has a lot of carbon deposits.

The most common cause of car shake is that the throttle is too dirty or the injector has too much carbon. When there is too much carbon deposited in the engine, the gasoline ejected from the cold-start injector is absorbed by the large amount of carbon deposit.

Engine cylinders are missing:

The lack of cylinder rental of the engine mainly refers to the abnormal operation of one or more cylinders of the engine, and the exhaust gas flow discharged by the car has obvious intermittentness, and the exhaust pipe shakes seriously, and the engine shake can be clearly felt, and sometimes it is accompanied by sudden sound, which is mostly related to the failure of the ignition coil.

The engine is flammable and the mixture is thin and thick;

Causes idle jitter after cold start. The lower the temperature, the greater the amount of oil required for the cold start, and the more carbon will be deposited, which will affect the success of the cold start.

If the car only shakes when starting, it may be caused by a problem with the dynamic balance of the wheels. After this happens, it is advisable to go to a professional tire shop to do a balance test on each wheel. If there are no problems with the dynamic balance of the wheels, it is advisable to check the engine and transmission.

High-speed rotating parts of automobiles need to be dynamically balanced, and wheels are no exception.

A wheel consists of a rim and a tire.

When manufacturing tires, the weight of each part is different, and when manufacturing rims, the weight of each part is different.

When the tires are mounted on the rims, the weight of the wheels is not the same, which can cause the wheels to shake abnormally when the wheels rotate at high speeds.

Therefore, the wheels need to be dynamically balanced.

For the dynamic balance test, the wheels are mounted on a special machine, and then the wheels are turned. The machine will detect which part of the wheel needs to be added with various counterweights.

After the inspection, the technician installs the counterweight in the corresponding position.

It is recommended that you re-test the dynamic balance of each wheel after replacing the new tires of Changdou to prevent the wheels from shaking abnormally at high speeds.

If the wheels shake abnormally at high speeds, it will affect the driving stability and handling of the car.