Adding Coolant:

WARNING: This page is about a different car, the 2003 BMW X5, 2002 BMW X5, 2001 BMW X5, and 2000 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: The tank mark indicates the fluid level at approx. 20°C.
Use only BMW coolant.

Turn on ignition.
Set heating controller to maximum temperature
Set fan to low setting. This opens the heating valves and starts the auxiliary water pump.
Perform filling operation slowly.
Pour coolant into coolant expansion tank up to max. cold fill level.
Close vent plug when bubble-free coolant emerges
Close coolant expansion tank.

Vent cooling system and check for leaks.