Only when refilling!
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2010 BMW 335xi, 2010 BMW 335i, 2009 BMW 335xi, 2009 BMW 335i, and 2008 BMW 335xi. However, it is still accessible from the selected car via links, so may be relevant.
Use only recommended coolant. Observe mixture ratio. See COOLING SYSTEM - OPERATING FLUIDS .
Perform filling operation slowly.
Adjust coolant level to MAX.
Close coolant expansion tank.
Installation note:
Close the sealing cap (1) until the arrows line up.
IMPORTANT:
The following bleeding procedure is necessary e.g. when a part is replaced in the cooling system or when the cooling system is refilled.