WARNING: This page is about a different car, the 2011 BMW M3, 2010 BMW M3, 2009 BMW M3, and 2008 BMW M3. However, it is still accessible from the selected car via links, so may be relevant.
TIGHTENING TORQUE SPECIFICATION - FAN
Type
Thread
Tightening specification
Measure
1AZ Fan clutch on water pump Coupling nut (left-hand threads)