So the plot thickens... Out of curiosity I used a pressure tester on the cooling system. Pumped it up to 20psi, came back about 30 minutes later, still at 20psi!

Could this all possibly just be a bad expansion tank cap? Going to pick one up today at the dealer and cross my fingers.

My money is on valley pan gasket. but I've been wrong "once" before. :)

Give us a feedback of that they say.

finally put the car back together, filled with coolant... ran the bleed procedure, let it run for about 15 mins. started the car, everything seemed file, let it warm up and got the "coolant level low" warning. let the car cool down, checked the coolant in the tank, it was reading full. ran the bleed procedure again, started the car again, same issue. whats the deal? did the level sensor fail all of a sudden?

Try few more times, and top it a little over the max. There may be a bubble in the system. Possibly leave the pump on for a good bit longer. :dunno:

well i drove the car around some more last night, let it sit overnight. topped off the coolant this morning and all seems well. low coolant warning is gone. URO pipe seems to be doing it's job.

Hey I'm planning to do parts of this, but planning to convert the coolant first to a waterless fluid (specifically Evans NPG+C). This requires removing the water based coolant as completely as possible - using their prep-fluid solution to help evacuate any remaining fluid from the drain.

Question is, can I rely on the electronic water pump drain procedure to do a fluid conversion? Or would I need to rely on a fluid evacuation kit that uses air pressure or something similar?

Anyway, excellent write-up. Really appreciate guys like you helping to keep the X affordable to the masses.

Great write up. I am leaking coolant through the weep hole and concluded the pipe is leaking. I already purchased the AGA pipe. My question is about the water pump. Does the water pump have to come out to do this repair?

No, if you're not replacing the water pump at the same time there is no need to remove it, the fan or any of the belts to access the valley pan. Also, removing the cabin filter boxes and the bulkhead parts only gives you slightly better access to the two rear intake bolts so I would forgo those steps as well

Thanks for quick response. :2thumbs: The dealer replaced the water pump 8K miles ago and I don't want to screw around with it if not needed.

Between the coolant leak and a bunch of oil leaks, I am really disgusted with this vehicle. No one should have this many issues with 82K miles on a high end vehicle professionally maintained and garaged kept. I was going to purchase a new X5 but I decided that I am not going to reward BMW with another $70K for their "superior" engineering.

I hear ya. I love driving the X5 but I sure don't love owning it. It's reputation and gas mileage worked well for us though as we bought it as a 3yo CPO for roughly half what someone paid for it new. It's never actually broken down on us but I have had to replace the coolant pipe, valley pan gasket, upper timing cover gasket, water pump and expansion tank. That's a bit for 4 year's and 35k of ownership but thankfully I can do all my own repairs so the cost hasn't been that bad.