N63 B40/B44 O 1 only
WARNING: This page is about a different car, the 2011 BMW 750xi, 2011 BMW 750Lxi, 2010 BMW 750xi, and 2010 BMW 750Lxi. However, it is still accessible from the selected car via links, so may be relevant.
Check coolant level when the engine has cooled down. Adjust coolant level to (A) approx.110 mm - 160 mm below the upper edge of the coolant filler neck. Use a tape measure where appropriate.