10 BMW 325i heating is not warm.

1. The thermostat turns on normally or turns on too early: the cooling system circulates too early and the external temperature is very low. Especially when the car is driving, cold air will quickly cool the antifreeze, the engine water temperature will not come up, and the warm air will not be hot.

2. The impeller of the water pump is damaged or lost: the flow through the warm air small water tank is not enough, so the heat can't come up.

3. There is air resistance in the engine cooling system: air resistance leads to poor circulation of the cooling system, resulting in high water temperature and warm air. If there is air in the cooling system all the time, it is likely that the cylinder pad is damaged and air leaks into the cooling system. If the inlet pipe of the small heating tank is very hot and the outlet pipe is very cold, this situation should be that the small heating tank is blocked and should be replaced.