A/C problems: Drivers side cool - passengers warm, & that darn hot/cold knob
 

Kind of a long post but trying to explain what happened...

The performace of my A/C didn't seem to be very good the past few days. I've owend my '04 X3, two weeks now and when I got it, the A/C seemed OK. (but it wasn't extremely hot out when I test drove it) Today it was 93F outside and I got very little cooling from the drivers side and darn neat hot air from the passenges side. Checking the temps with a thermocouple confiremd it. Best it would do was 85 from the drivers side and 99 from the passenger side!! To make things more confusing, when I turned that temperature knob between the vents from three blue dots to three red dots, it droped both temps 4 degrees. (to 81 drv, 95 pasx) WTF? :loco:

Searching the forums I found several posts that mentioned similar problems, (only on the X5) but no one really posted why there is a difference between the drivers and passengers side.

Since the A/C no longer was blowing cold, I hooked up gauges and it was reading 25 on the low side and 135 on the high. I don't know what BMW says it should be, but folks I talked to said that was low. I picked up a can of R134a and it took about 3/4 of it. Pressures were now ~ 45 and 180 and I was getting ~ 59F air from the drives side and ~ 68F air from the passengers. I wonder how long it will last.

Have other X3 owners had leaky A/C systems? X5 posts I found talked about needing the servicing valves replaced. Where are those located?

Does anyone know why the air from the passenger vents is warmer than the drivers? When you crank down the temp set point, it makes no sense to have the passenger side putting out warmer air. The system is fighting itself to cool the cabin! Grrrrrr. It's as if there is a vave that is ducting some of the passenger air over the heater core.

Thanks,
Chip

Put the temp' knob between the vents on max' hot and leave it there, otherwise the system doesn't seem to work properly. This knob is only meant to be used in winter when the climate control is calling for hot air and you want some cold air to blow on your face when feeling drowsy.

I don't think this is correct--I run mine full over to the blue in summer--it the air from the dash outlets feels too cold I move it towards the red and the upper and lower outlets remain cold. I wonder if you have some door control problem--Could be that the doors are controlled by the body computer--what you describe would be how a dual climate control works--of course the X3 does not have this. I have noticed that occasionally the dash outlets don't feel real cold--I press on the 3 zone buttons and it works better--try this out..

:thumbup: HI this is jose from puerto rico;I'm not sure but mine did the same ,at the dealer told me that bmw cars did that as a safety feature (blow cold when low on freon by the driver to defrost the driver glass in case will needed) mine has to be replace the seals kit in the A/C compressor...hope this help
bye have a great day

A friend of mine has a 01 330 that has an AC leak and when the freon i s low the passengar side blows warmer air. Once the freon is replenished the AC works fine.