What are the hazards of idling for 2 hours and idling for a long time?

Idle speed is to stop at the same place without stepping on the accelerator, so that the engine can work at around 800 rpm for a long time.

Idling for a short time has no effect on the car. Idling for a long time, such as 1 hour or more, is not very harmful to the car, but it has the following two hazards:

First, idling is easy to burn oil. When idling, the throttle opening is small, and the vacuum inside the intake manifold is high, so it is easy to suck oil and gas into the intake manifold, and part of it is deposited inside the intake manifold, forming substances similar to carbon deposition, or coking. Long-term low speed or idling, especially turbocharged cars, will find a pool of oil in the intake manifold behind the throttle, but these oils will generally disappear after running at high speed.

Second, idling is easy to accumulate carbon. When idling, the mixture will generally be thick, so the mixture will be thick after a long time, which is easy to cause carbon deposition in the engine. The same is true of stop-and-go driving at low speed, such as "one foot on the accelerator and one foot on the brake". As soon as the accelerator is put on speed, it will brake again, and the engine will thicken for a while, and the fuel injection will be reduced for a while, which will also cause carbon deposition in the engine.

Generally speaking, idling for a long time has little damage to the engine and little wear, so there is no need to worry about engine problems, that is, it costs more oil, and then it is easy for the engine to consume oil and cause some carbon deposits. Generally, it's nothing to be idle for ten hours. Some people forget to turn off the engine, idle for one night, and then the fuel tank turns off when there is no oil.

Even if idling 10 hour, no remedial measures need to be taken. Just maintain the engine regularly and change the oil. Now the engine is not so fragile, and it will be fine to idle for a few days. Try to avoid idling for a long time in the future