Pull out the pipe in the car water tank and deflate it.

According to what you said, your good friend suggested that you flush the water pipe at the highest position on the engine and bleed air from here! Remove the straight end of the highest water pipe. Then add antifreeze to the water tank. When there is no air in the water pipe head, quickly install the water pipe connector. Then, after the electronic fan with headlights automatically rotates, touch the temperature of the upper and lower pipes of the water tank by hand. If it is the same, it proves that the thermostat is on. At this time, it is normal that the antifreeze in the water tank is insufficient. BBA Mercedes-Benz BMW Audi car wishes you a happy life! Happy family! The financial resources are rolling! If there is something wrong with the car, ask the car master. 4S shop professional technician, 10 minutes to solve.