Do you have any updates on your A/C problem? I been doing research as my A/C started being warm yesterday. It did it before a year ago, I had an independent shop check it out and couldn't find any leak, a year later here we are. I've researched and also asked an Audi technician friend (no longer works for Audi) and he said the rear evaporator is almost all the time the culprit. I was wondering if you have addressed your problem yet..

dye yes is added to the A/C system to help identify any leaks. Sometimes the leak will be fast, sometimes it will leak over time. But if it is leaking, it will show.

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Hello,
The dealership did a recharge on the AC system and added more refrigerant and said the AC is working properly now. They did the dye test and said they didn’t find any leaks. We are letting them keep the car for a few extra days so they can drive it around and see if the problem happens again. They didn’t think the evaporator is the problem. I’ll keep you posted when they call back next week sometime.

I spoke to another memeber that had the same problem, and dealer added dye, recharged and checked for leaks and nothing. 1 year later he said his a/c was warm again and there was a wet spot in his garage where it was leaking. So it might not show up immediately. Mine took 1year almost to the date for my a/c to get warm again. Took it to the dealer and they confirmed it was the rear evaporator that was leaking. They replaced that and also took care of the fuel pump recall at the same time. Just picked my q7 up yesterday and the a/c is noticeably colder than I could ever remember.

Your dealer should really look into the rear evaporator being the cause of the leak. It’s kind of a common problem.