Hi everyone. New to BMWs and this forum. I mostly look around can get info but I'm totally stuck...
I have the exact same problem. If it is the heater valve, can I swap the hoses coming out of the duovavle and see it the problem transfer to the other side.

Just an idea to accurately diagnose the issue. Thanks guys :)

First thing I recommend, as I wrote earlier:

"As an update to the thread I put on 1,500 miles on my trip and my AC worked great after the re-charge. So if you experience the problem in the thread title, having the refrigerant level checked should be your first course of action since it is the least expensive potential fix."

:iagree: Had this issue last year and was told there was a leak in the system. Had it re-charged and it is still blowing cold out of all vents.

Topped if off today. It was just a lil bit low (few ounces) the temp dropped across the board but still a considerable variance in temperature in the vents.

What controls the main heater core? Meaning what stops the hot water from entering?

Check the dial in the center of the console for the top vents. I have mine set to one blue dot in the summer. This dial controls the distribution of the AC or heat to the upper/lower vents.

The heater control valves. They can get rusty/clogged a bit and not fully close, allowing hot water to seep into the heater. A quick test would be to see if the AC performed normally on a cold start, (the first start in the morning) and only cooled unevenly after driving a little to get the coolant hot.

Tried that this morning. X5 heats to operating temperature to quick for me to see is ac is running normal.

I'm curious as to how cold is the AC supposed to blow.. Meaning My X blows air but it feel luke warm or cool out all vents. Is it supposed to be so cold that if I hold my hand in front that my hand will be cold. Example if its 96°f outside and I use max ac button set at (60°) it blows cool air not ICE cold (1-3 blue dots). Then if I switch to auto it goes down maybe 3 lines as it cools the interior for a 15 to 30 minute drive set at 75°. Am I having early signs of the failure everyones mentioning or this is normal for the X.

can you just clamp one of the hoses and bypass the hcv?

Having the same problem you originally described. It's 87F ambient temp and the unit is blowing about 60F - 64F air on the left side, but feels like ambient or even a bit like heat on the right side. Checked pressure and I've got 40 psi on the low side (35 before it gets hot, and jumps to 70 when I cut it off). I tried adding some 134a, but it won't take any. Weird. Really makes the most sense to me that it would be the heater control valve(s), but then I read your story about how adding the 134a fixed it. Confused. Thinking about blocking off the valve and/or heater core to prove if it is the valve or not. I know in other domestic vehicles for decades in the past folks would do this, and I have done it myself, too. I knew one guy who installed just a standard gate water valve in place of the heater control valve, and he just raised the hood and opened/closed the valve whenever he wanted air or heat.