What should I do if the cooling effect of BMW 5 Series is not good after replacing the new water tank?

Check the air conditioning system and find that the heating pipe is blocked.

1. Use a computer to check the car body and air-conditioning system to see if there is a fault code. Secondly, if the antifreeze is not hot enough and the air is not discharged, you need to check the water pump and heating valve. Is there any problem? The water circulation is not good, and the heater water tank is also checked to see if it is too dirty. The heating effect is not good due to poor water circulation.

2. It may be that the heater water pipe is blocked. You can judge this by yourself. Open the engine hood and touch the upper and lower water pipes of the heater. If the temperature difference between the upper water pipe and the lower water pipe is relatively large, then It's just that it's clogged. If it's clogged, the warm air won't be hot.