Coolant Leak on X5 50i (N63) 2013

[Nanometer]

Hey All! I have the described car and it has a coolant leak coming from the driver side. Approximate location is between the heater core ***** which appear to be dry, and the reservoir, so basically somewhere in that region. Do you guys have any idea what that could be? Recent replacements were Thermostat, and the "T" fittings which are on top of the engine. Engine was leak free for a few months, and then this issue popped up seemingly very suddenly. Pressure Testing at 15 PSI creates a sizable puddle pretty quickly. Really appreciate your guys' thoughts!
Potential issues: Reservoir, some coolant line that I can't see?

[Nanometer]

Adding a picture. Area for leak is in red. Basically the bolt get's wet when I pressurize the system. I know it isn't easy from this picture, but hope it helps!

[Ryan5034]

There is some sort of heater control valve down there. That might be it. Make sure your coolant expansion tank isn't cracked.

[Nanometer]

Thanks for the suggestion! I'll check the valve. I think the tank is good, the leak is much further back.

[NVS PWR]

The system is not overfilled right? Of it is ot will vent out and make a mess. Always good to check the very simple basics. Also if the turbo coolant pump is starting to fail- the system will leak when vehicle is shut off.

[cd85233]

Put some dye in there and let it run for a bit. Should glow like a light under UV. Doe the turbo tanks/main tank at ones.

[jaydavis226]

Hello,
out of curiosity did you ever find out the problem?
I’m pissing coolant on driver side just behind the tire. I purchase dye just waiting to arrive.
I had hi temp warnings on start up so i replaced the turbocharger pump but I’m still getting waring on start up.
I also want to add the coolant level has not really dropped.
The turbocharger coolant and pump now run with zero coolant lost.
2011 n63 with 70k

[9vapors]

Mine was my water pump and then coolant tank. The coolant tank leaked right in that area for me... they're prone to cracking.

[dennik]

+1 for coolant tank, i also replaced at 83kmiles