1, cold start jitter

First of all, from the cold start, the main reason for the body shake during cold start is insufficient fuel combustion, which leads to insufficient power of the car. The ignition energy is low, and more oil is needed to meet the power when starting, especially when the temperature of fuel and lubricating oil is low. After a long time, the gap between the two poles of the spark plug gradually becomes larger, which leads to the reduction of ignition energy and poor fuel atomization, resulting in body jitter. In addition, the aging of ignition coil, aging of spark plug high voltage line or leakage will also lead to the decrease of ignition energy.

2, the problem of shock absorption system

Body shake is also related to the aging of shock absorber system. Mainly responsible for filtering out the vibration when the engine is running. If there is something wrong with the shock absorber, these vibrations will be directly transmitted to the steering wheel and cab, which will affect driving. When the engine is idling, turning on the electrical system in the car is also easy to cause jitter. The engine will increase the load because of turning on the electrical appliances, which will lead to the decrease of idle speed, and in order to make up for the jitter caused by the decrease of idle speed, the engine will automatically increase the speed. Therefore, when turning on the electrical system, especially the air conditioner, the engine will often shake. This jitter is probably caused by the aging of the shock absorber and needs to be replaced in time.

3. Tire problem

For tires, wheel balance should be done when replacing new tires and rims, otherwise the steering wheel will shake easily when the counterweight is uneven. If it is found that the tire balance blocks are uneven, lead blocks need to be added inside the steel ring to make the tire balance blocks on both sides evenly balanced. Whether it is a general steel ring or a light aluminum ring, it may be deformed or broken when subjected to a certain external force. The deformation of the rim will cause the jitter when driving, the uneven weight of the rim will also cause the jitter when driving, and the incorrect angle of the rim will also cause the jitter when driving.

4. Throttle problem

The most common cause of automobile jitter may be that the throttle valve is too dirty and the fuel injector has too much carbon deposit. After a few kilometers of driving, the dirty throttle will lead to untidy throttle closing or motor jamming, which will lead to excessive idle speed of the engine, and the carbon deposit generated by the engine in this process will also lead to vehicle jitter, especially when starting the vehicle, the engine jitter will be more serious than usual, and sometimes it will even be impossible to start at one time. Therefore, when the car body is shaking, the throttle and throttle should be checked first. If it is found that the throttle is too dirty or the fuel nozzle has too much carbon deposit, it should be cleaned with fuel nozzle cleaning agent and throttle cleaning agent in time.

5. The oil pressure is unstable

The engine carbon deposit has been cleaned, the throttle valve has been cleaned and the oil cushion has been replaced. If the car body is still shaking after all this, I suggest you go to the repair shop to check whether the fuel supply pressure and intake pressure sensors are normal. If the oil supply pressure of the oil pump is abnormal, the numerical error and improper operation of the intake pressure sensor will cause the body to shake.