There is water behind the throttle.

Leakage of intake manifold or various valves. When the air intake of the engine is wrong, it will cause the mixture to be too rich or too lean, which will make the engine burn abnormally and lead to the engine idling jitter. When the position of air leakage affects the vacuum degree of the engine, the engine will shake violently, which has a great influence on the idle speed of the cold car.

Automobile engine maintenance method

Using good quality engine oil, that is, engine lubricating oil, can play a role in lubricating, cleaning, cooling, sealing and reducing wear and tear of the engine. Only by using qualified lubricating oil can the wear of engine parts be reduced and the service life be prolonged. Therefore, attention should be paid to adding good quality engine oil, and it is not allowed to let the engine run out of oil.

Using qualified coolant antifreeze, it is very important that the automobile engine needs to rely on the water tank to cool down, otherwise the engine will easily "boil" and cause fatal damage to the engine. So be sure to keep the coolant in the water tank at a normal level, choose a good quality coolant, especially in winter, and choose a suitable coolant according to the ambient temperature. In the normal maintenance of automobiles, engine antifreeze needs to be replaced every year.