I had an issue in our '05 X5 3.0i where it quit blowing cold air until you were at some road speed. Turned out the aux. fan was not working and it was causing the compressor to shut down at lower vehicle speeds (i.e. surface streets/stoplights, etc.) where no significant air was blowing over the coils. Ordered/installed the aux fan (per how to posted here somewhere - thanks!) and it fixed it immediately and completely.

BTW, in calling to try and beat the rediculous list price on that part, I called Chattanooga BMW, a dealer advertising in the Roundel. They claimed 30-40% off list for BMWCCA members, the steepest discount I'd yet run across. I've since ordered a bunch of things from them and their prices are always the best I've found. The fan was over $500 here in So Cal, but was $380 from them. No affiliation, just a happy and now repeat customer.

there is plug-in cable that goes in at the top of the compressor. the contacts may have become loosened or bad due to oxidation over the years. so the compressor may work intermittently. if you know how to remove the air filter housing, you can gain access to this plug. either try pushing it in to see if the compressor starts running or perhaps use a sand paper to sand off the carbon/oxide on the electrical contact surface. hope this may do the trick.

http://www.realoem.com/bmw/diagrams/c/j/90.png

Same A/C problem
 

My 2006 3.0 just started to have the same problem presented by the OP. I'm bumping this to see if anyone has new insights or experience on this random perplexing A/C issue.

For me the problem was easily resolved with the DIY freon fill up.

AC Problem
 

I have exactly the same problem. It is working fine then suddenly the cold air is gone. When i turn on the demister on max the hot air blows out small chunks of stuff. Then i go back to ac and the air is cold again. I dont know what the deal is. Im in SE Asia and there are no BMW techs where i am living. I have to go to another country to fix it and pay a fee to register my car at the BMW dealer about 500us before they will even check my problem and fuck my ass for more $$$$.:cool:

I have a similar issue - Compressor engages intermittently (eg.g after disconnecting the battery for a while).
What could this be - I doubt low gas because it blows cold when compressor engages (should it not be warm when pressure is low)
Confusing??

I have the same problem with my 05 x5 3.0d. Indie mech tells me that it is common with older x5's and doesn't know why. Aircon eventually starts after 10 to 15 minutes and is okay for rest of starts that day.

after 3 months suffering from this problem, finally the compressor said his word and completely stopped working .. i just replaced it ... good luck guys :)

I'm having the same problem with my ac as well. My AC would work for a while, and then the ac would stop and start blowing regular air. This is my first X5, and I am already experiencing this kind of issue......sigh....:confused: