2007 R56 S with 100k. My AC blows cold air for a few seconds then warm outside air. It also makes a inconsistent noise coming from the center of the dash that sounds like a swishing/shhh sound. I have a DTC E734 fault code. any ideas? Thanks.

 

I don't know what the fault code is, but my first guess is that you're low on refrigerant and probably need a recharge.