Antifreeze is used as a coolant - a mixture of ethylene glycol (40%) and distilled water (60%).
Attention! Antifreeze is an aggressive liquid for the skin, is acutely toxic when ingested and destroys paintwork.
It is prohibited to remove the filler cap (Fig. 2.22) until the engine has completely cooled down (to a temperature of about 20°C).
Checking the coolant level of the BMW X5 E53 must be carried out in the following order:
- release excess pressure in the tank by slightly unscrewing the cap counterclockwise, then open the tank;
- the coolant level is normal if the upper end of the red rod of the float mechanism (arrow) is at the height of the upper edge of the filler neck. It is acceptable for the end of the float to protrude above the edge by no more than 2 cm, see the diagram next to the neck (Fig. 2.22);
- slowly add the required amount of liquid, avoiding overflow.
- If the coolant level drops systematically, it is necessary to locate the leak in the cooling system. Inspect the engine cooling jacket, radiator, hoses, expansion tank filler cap, drain plugs, and coolant pump. Check the tightness of the expansion tank filler cap.
- Using a hydrometer, check the concentration of antifreeze. Check the cleanliness of the coolant itself, if a change in color is detected, which becomes brown or rusty, flush the cooling system and replace the antifreeze. The frequency of replacing antifreeze is every two years. Check the tightness of the entire system. Drained antifreeze is subject to disposal.