1, one is caused by the engine cooling system;
2. The control mechanism of warm air doesn't work well.
Problems like this are all hardware problems and can't be solved by themselves. Need to go to the repair shop for repair. But you can judge for yourself what kind of problem it belongs to, and the judgment method is:
If the metal pipe of the water tank is hot, it is the cause of the failure of the control mechanism, and if the water tank is cold, it is the cause of the failure of the cooling system.
Extended data
Don't turn on the warm air immediately after the car starts.
In cold winter, don't turn on the warm air directly after the car starts. Because the car has just started, it takes some time for the engine oil in the car to lubricate all parts. Once it is started, the warm air is directly turned on. Due to the lack of internal lubrication of the engine, the friction between parts is very large.
Moreover, the high load of automobile engine not only wastes engine oil, but also wears automobile parts. It is recommended that you warm up the car for 2-3 minutes after starting, and it is best to turn on the warm air after the scale on the water thermometer rises.