In the maintenance of our car, the owner should be able to change the antifreeze by himself, which is not very complicated, so many owners will change it by themselves.

However, if the air in the cooling system can not be properly removed, it is easy to cause the phenomenon that the water temperature of the vehicle is too high. This is because there is too much air in the cooling system, which makes the coolant unable to circulate effectively. In addition, the air is heated and expanded to produce too high pressure. At this time, if the water tank cover cannot release the pressure in time, it is easy to produce serious failure of water pipe or even water tank burst. Therefore, after the antifreeze is replaced It is essential to exhaust the air.

So, for BMW models equipped with electric water pump, how to exhaust the air after changing the antifreeze? Here are the steps:

1. After filling the antifreeze, cover the water tank cover, insert the key, turn on the ignition switch (or press the start / stop button without pressing the brake);

2. In the warm air mode of air conditioning, the temperature is adjusted to the highest, and the air volume modulation is the smallest. This is a very important condition. Only in this state, the electric water pump can operate to make the antifreeze flow in a small cycle;

3. Driving light on status, that is, turn the headlight switch to the right for one gear;

4. If you don't start the engine and step on the accelerator to the end, you will hear the sound of the electronic water pump working in about 10 seconds;

5. The electric water pump will run for about 12 minutes;

6. After the water pump stops running, open the water tank cover for inspection. If the liquid level is lower than max, add antifreeze to max;

7. If it is necessary to exhaust again, reset the DME completely (remove the key for more than 3 minutes, or press the start / stop button for more than 3 minutes), and then start again.

matters needing attention:

1. If you think your battery is about to last, it's best to start with an external charger.

2. The exhaust must be carried out when the engine is cold.

3. It is forbidden to open the water tank cover or drain valve when the antifreeze temperature is very high to avoid scalding.