You guys are making it hard. Is the blower motor working..... The X5 hoses have been known for dislocating from time to time.... Best advise.... Take it in to a independent service shop... Screw BMW's warranty.... The only thing they put on their service sheets is "unable to duplicate problem".... Do some research and find a good shop... Ps. Turn your ac up all the way... Turn off any radio or headlight... When the car is idling.... Turn the ac on and see if there is any rpm difference.