is the temperature the same coming out of all the vents? mine wasn't and fixing the water valve fixed the issue. indy said water valves are common replacements for him.

http://www.xoutpost.com/bmw-sav-foru...failure-6.html

http://www.xoutpost.com/bmw-sav-foru...pressor+clutch

The first link is the link I followed to help me with my repair. The second link is my post while doing my repair. These were both on 3.0's I believe.
Getting the AC compressor out is standard for a BMW. First you have to remove everything else under the hood then you can get it out.:D I tried to make the swap with the compressor still on the vehicle but did not have enough room. Ended up having to remove it which included cracking open the system and then having to reseal it, vacuum it, leak test it and refill it.

Make sure your diagnosis is correct before you start replacing stuff or you could spend more than what the correct repair would cost. Do a several searches on "ac problems", "compressor coil", etc. and do some reading. That is partially how I figured out my problem. I was all set to order a $450 AUX fan when I was able to properly diagnose that the AUX fan was not the problem.

Repoman, thanks for your advise.

Just one thing I have noticed today, car is ideling, when I press the AC button the rev go up ever so slightly, press the AC button again to turn it off and the rev drop to normal. Would this suggest the AC compressor is coming on?

No, this does not mean that the AC compressor is coming on. What it does mean is that kick-down is working properly which is seperate from compressor function. Mine was also kicking-down everytime I pressed the AC button but no compressor lockup. It will still kick-down even if compressor is not working properly.

The only way to verify is to put your eyes on it. There's no other way I can tell you verify it and can't really help any further if you can't verify it.

Find the compressor, push the AC button and look at the part in the center of the compressor pulley to see if it is spinning or just sitting still. There's no other way to tell!

How do I see the clutch?
 

Hey all,

I am having the mysterious A/C slash Aux fan problem too. I am trying to see if the compressor clutch is engaging but I don't have an angle on it. I can see the top of the compressor but not the center of the pulley. I have a 2003 3.0i. AM I missing something here? Do I need to get under the car or use a mirror on a stick or something? My indy mechanic (who does a fair amount of BMW work) says the pressures on the compressor are really low (he says basically the compressor is not compressing), but it seems to me that this would be true if the clutch was not engaging, and I am not sure he knew to check for that. He believes my aux fan is shot too, so I don't want to replace the compressor ($1200 from dealer) if the problem is the aux fan anyway. Any hints on this?

You should be able to get your hand in to feel if the pully is free, Take off the air duct and air box if required.

My AC issue was resolved not by replacing anything but in fact plugging in the power cable to the AUX fan which had not been plugged back in by BMW!! when I had the waterpump replaced ealrier this year, I was going to take my X5 to a car electrical specialist as these faults tend to be more electrical than actual AC releated.

Yikes! Is that safe to do while the engine is running? (putting my hand in?) When I get home I will try to look at the box and duct you are talking about and get them off.

Would it be easier just to get under the car, I wonder?

No, the engine will be off, once you have your hand in you should be able to manually move the compressor pulley, This will only tell you if the compressor is seized or not. There is plenty of reading on this forum for the 3.0i engines and AC issues and fixes. Also allot easier to get your hands in to check things compared to the 4.4i lump, might be worth unplugging the AUX fan power lead, cleaning and reseating. It might be this, if not check it has 12v going to the AUX lead.

Were can I find the AUX fan power lead on a 06' 3.0 ?

picture one in this post shows the socket. If looking into the engine bay it on the top right of the innner fan. The picture shows the cable missing, unplug the cable and test the voltage when the AC is turned on and off from the temp controller in the dash.