What is the reason for the loud engine noise when the new energy vehicle starts with fuel?

Hello, when the new energy vehicle starts the vehicle with fuel, the engine sound is very loud for the following reasons:

Due to engine mechanical failure, the valve is not closed tightly, and the cylinder pressure of each cylinder is different; The throttle valve in the air supply system is dirty or damaged; The pressure of the oil supply system is too low or fluctuates greatly, and the injector is seriously carbon-deposited. Generally speaking, the more cylinders the engine has, the lighter the engine idle jitter is, while the in-line six-cylinder engine has the best ride comfort because it can automatically balance the vibration in structure. However, the riding comfort of the three-cylinder engine widely used now is extremely poor, so it is necessary to design a balance mechanism to maintain normal operation.

If you can obviously feel the vibration of the car when you are sitting in the car, feel your hand holding the steering wheel shaking, the pointer of the tachometer jumping up and down, or open the hood of the engine, you can obviously see the engine jitter, indicating that the engine idling jitter is too large. At this time, look at the engine data flow with the engine scanning tool, and you can see that the engine speed value is fluctuating. Under normal circumstances, the engine speed will not jump up and down more than 30 revolutions. If this value exceeds 50 revolutions, it can be judged that the engine idling jitter is too large.

I hope I can help you!