Might want to consider this as an option - Bimmer Fix | Coolant Pipe Repair System

My water pump bearings went at 78k on my 2008 so I am doing this while I have my water pump off.

Also suggest anyone with a 4.8l to PM the water pump by 75-80k just to be on the safe side.

Replace the stub pipe from the rear of the water pump and the plastic pump pulley as well.