Air conditioning air warmer on passenger side

[80stech]

Yep there have been lots of posts about that happening like Haigha has said.

Do as I told you and rule out the heater valves.

[Fifty150hs]

Originally Posted by Masospaghetti

Low refrigerant would not cause the air to be warmer on the passenger side only, correct?

Do a search on the board. I seem to remember someone several years ago with the same symptom and it was low refrigerant.

Also, be careful on the rebuild kit. I bought one when my valve went bad a number of years ago and none of the parts fit. I have an '06, so BMW may have changed the valve design at some point.

[Masospaghetti]

ok that makes sense then. I'll command the heater to open and check the temps. if that looks good I'll check the refrigerant (I have a manifold set I can use).

[andrewwynn]

If your scanner can read the heater core or evaporator temps that's beyond helpful.


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[haigha]

Originally Posted by Masospaghetti

Low refrigerant would not cause the air to be warmer on the passenger side only, correct?

Yup, same symptom as others have confirmed. Every year for me now, used to have to recharge every other year.

Here's my original thread on the topic...

https://xoutpost.com/bmw-sav-forums/...ht-thread.html

[Masospaghetti]

Ok, did a bit of work today on this. I dusted off the old manifold set I haven't used in years and had to fix a leaky coupler and unearth the charge adapter, but after all that I got to working...
I added some refrigerant which did reduce the asymmetry in the vents but did not eliminate it. I stopped adding when the low side pressure got to 38 PSI and high side 220 PSI. At 80 F 80% RH, left vent at 50 F and right vent at 60 F.
If I understand correctly the X5 uses a variable displacement compressor which should keep the low side pressure between 28-32 PSI at all times, and if it exceeds that then the system is overcharged. Is that correct?


Edit: Got INPA working - this shot is with the A/C on a low setting (NOT MAX A/C):

[andrewwynn]

EVAP 11c matches the colder side. Both heater core cold so it's not coolant valve.

Feels like outside air leaking in but why only going one side? There's a flap somewhere to regulate hot/cold for right side vs. left it has to be letting more fresh air into right side vs. left.

Air mix set to 3 blue? And what happens when you change to recirculation air vs outside and are tit trying to outsmart the automatic setting? Should be set to automatic and a reasonable temperature like 72°F which it may have been: thought i saw 22c=71.6 F on one of the readings.

What year is your X? On our 2001s, the low side was much higher when charged but when it got lower like 25 psi, it would freeze the evaporator.

What happens to EVAP temp at Max cooling? Should see EVAP temp around 3-4c


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[80stech]

The system is extremely sensitive to having the right charge so the only way to make sure is to evacuate and charge with a scale. Take readings with at least 3/4 fan. If cooling is good I wouldn't worry about getting both sides exact. What did you find out with the heater valves ?? The right side of the screen shot is missing, at least on my computer ??

[andrewwynn]

Heat exchangers were 9 and 11c on the screen shot indicating coolant valves both closed.

Evaporator should get down to about 4, but it wasn't on Mex. I think the disparity left/right is the concern and 10F is a pretty big difference. What are the two sides set to when those readings were taken?


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