I have an 2006 Audi 3.2 QUATTRO and I think It has a problem with the AC.
When I turn the AC on (between 69 to 74 grades Farenheit) it starts blowing cold air for a while until the temperature inside the car goes down, after that it starts blowing hot air, I even tried turning the AC down but it kept blowing hot air. I guess is an AC factory malfunction and the car's computer is trying to keep the inside temperature I set at the beginning and when is too cold it tries to keep it up blowing hot air.
The only thing I know about AC's, is when the temperature goes down, the AC should turn automatically off until the temperature raise up and then it turns on by itself again.
I took it to the dealer and they didn't found anything, but the problem continuos and is annoying when it starts blowing hot air during summer time. It works fine when the AC is set at the lowest temperature but then it is too cold.
Please if someone knows what is the problem about, let me know.
This is caused by a faulty climate control valve that was fouled during the manufacturng process. The valve sticks and will not properly divert coolant, causing hot air on the outside vents and cool air in the center. Very annoying in the summer time. There is a Tech Service Bulletin out on this from Audi, they do not cover it out of warranty. The part number is 4f1-959-617-b. I am replacing mine today...