Originally Posted by axgordon

X5Only, you are following my footsteps! I purchased 2005 4.4 with 113000 miles and the first thing I did is the dreaded alternator bracket oil leak fix and while I was under the car I noticed coolant dripping overnight from the exactly same spot as on your pictures! In my case I traced the source to the back of the valley pan – use an inspection mirror and powerful flashlight and you’ll be able to see back of the valley pan without removing any parts. I was planning a cooling system refresh anyway, so I did swap water pump, thermostat, radiator hoses, etc. Also, I installed collapsible coolant transfer pipe (under the valley pan), but it was unjustified in my case – the old pipe and seals both proved to be in the very good shape. I don’t know service history of your car, but based on the age / mileage I would do valley pan only. There’s plenty of DIY for this job on multiple BMW forums, so I will not go into details here. I think if you do choose to replace just a valley pan, you can do the job in a few hours with ~$150 for parts. To do just a valley pan, you will need:
Valley pan, Intake manifold gaskets, valvetronic motors seals (O-rings), short coolant pipe between water pump and valley pan and antifreeze if needed. Also I installed new valley pan bolts.
The job is not that difficult for the average DIYer and does not require any special tools. Be careful with breather hoses and other plastic parts. Please do not hesitate to ask questions – this forum is one of the best resources available to BMW DIY community. Good luck.