There was a sudden noise when the car refueled yesterday. Is it normal?

The reason why the car can't refuel suddenly is that the engine is short of cylinder, which will lead to insufficient refueling power, obvious exhaust gap in the exhaust pipe and violent shaking, thus making a sudden noise like a tractor. The lack of cylinder in the engine is mainly due to the high concentration of mixed gas or the poor operation of spark plug. There are many reasons for these two failures.

First, the mixture is too thick, causing the car to get stuck when it can't refuel.

Under normal working conditions, the combustible mixture ratio of the engine is: air/fuel =114.7. Too little air or too much fuel will make the mixture concentration higher than this ratio. If the concentration of the mixture is too high, the deflagration sound will suddenly sound, and the engine cannot refuel.

The causes of air shortage include air flow meter failure, throttle carbon deposition, throttle motor failure, air filter blockage, oxygen sensor failure and so on.

Fuel concentration may be caused by the failure of fuel pump, oil dripping from nozzle, failure of water temperature sensor, etc.

Second, the spark plug is not easy to use, which causes the car to get stuck when it can't refuel.

At present, the ignition time of automobile engine is controlled by computer. When the ignition timing is wrong, the high voltage bag fails, the voltage of the generator or battery is insufficient, and the ignition gap of the spark plug changes, the mixture will burn badly or ignite badly, resulting in sudden abnormal sound when the cylinder is missing.

Incorrect ignition timing may be caused by the failure of camshaft position sensor, staggered timing chain and knock sensor.

The change of spark plug ignition gap may be caused by carbon deposition or collision with spark plug side electrode during installation.

Insufficient generator power may be caused by belt slipping, generator carbon brush wear, generator voltage regulator failure and other reasons.