This is my first post in an attempt to help those who have the AC delay problem like I did on my 06 X5 3.0; which I spent a couple of weeks before resolution. Bought used w/ 75k miles 8 months ago and always had my delay after the car was off for many hours (like overnight or after a 12 hour shift), the AC would blow ambient temp until I was down the road a couple of miles then instant cold AC.

The problem ultimately in my case occured when the hi and the low sides of the compresoor equalized, which takes many hours once the AC was off (this is norm). Even after a few hours when the pressures were not yet equalized the AC would immediately blow cold and stay cold even at idle. I verified this renting gauges from Autozone and was able to duplicate the problem by shutting off the AC (after it was working) and slowly bleeding the high to the low side until pressures were equalized. Then turning on the AC (comp engaged) the pressured stayed equalized (no cold) until either I reved the engine enough to cause a slight difference in pressure then the presssures would instantly move to norm high and low.

My take on it (not being a mech engineer) is that it is something in the comp similar to a hung open or closed suction or discharge valve, or it is something else not seating or resetting until there is enough difference in pressure to hold force on it to work. The discharge line of the comp stays ambient to the touch so no vapors are leaving the comp at this time.

Like most everyone, I thought it was the fan, pressure switches, freon level etc. I changed out the PCV on the comp itself and that did no good. I bought a remanufactured comp and installed myself and only changed the dessicant dryer media, prob solved. Guess you can say good news is that the comp did not lose pieces (no major damage) so the repair did not include the expansion valve and condensor and flushing as would be required for warranty usually when installing a new comp.

Just to note, when I received my remanned comp, I could hold my finger over the discharge, turn the comp by hand and pressure would build behind my finger. When I removed my problem (orig) comp it would not build pressure by a hand turn.

Not the answer some wanted but hope this helps.