WARNING: This page is about a different car, the 2013 BMW X5 M, 2012 BMW X5 M, 2011 BMW X5 M, and 2010 BMW X5 M. However, it is still accessible from the selected car via links, so may be relevant.
TIGHTENING TORQUE SPECIFICATIONS - FAN
Type
Thread
Tightening specification
Measure
1AZ Fan clutch on water pump Coupling nut (left-hand threads)