1 and BMW 520 turned on the warm air, and the antifreeze was gone, and there was an odor, indicating that the BMW 520 warm air box was leaking, which led to the decrease of antifreeze. The heating box is found to be leaking and needs to be replaced.
2. Damage to other parts of the cooling system will lead to antifreeze leakage. Inspection found that these parts were damaged and needed to be replaced.