Illustration Shows E65/E66:

WARNING: This page is about a different car, the 2005 BMW 645Ci and 2004 BMW 645Ci. However, it is still accessible from the selected car via links, so may be relevant.

Perform filling operation slowly.

Pour coolant into expansion tank (1) up to MAX mark.

Start engine and run at idle speed for approx. one minute (cap open). Then adjust coolant level to MAX.

Fig 1: Locating Expansion Tank Coolant Filling Mark (E 65/E 66)

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Close cap and run engine up to operating temperature until main thermostat opens. Check cooling circuit and drain plug for leaks.