What the hell!!!! This is our second Audi and the A/C bites just like the last one. Took a trip through upstate NY today temp was around 90 and I think it was 90+ inside A/C was barely coming out the dash vents yet it sounded as if the defrost was on high, stopped at a auto store picked up some 134A with gauge put it on and showed it was a little low pumped in some refrigerent and works a bit better but still no great hell.

Driving home at 9:30 temp outside was now 80 and had the system set at 70 still no good, should have been freezing inside but NOOOOOO!!! any ideas.

 

Need to do a Vagcom reading....it will check all internal flaps/flap motors. Probably have a problem with temp control/mixing.
If you low pressure line (in fresh air plenum left..I believe) gets cold and swetty, you probably have icy cold evaporator, but not getting air routed to the vents correctly.

If your low pressure line does NOT get cold, you could have an under the hood (compressor?) problem.

 

The one line (small line under hood) had ice on it which should be the return line so maybe it is a compressor problem?

 

The return line is the low pressure line...should get very cold....iced over? ...probably not(?)
I'd still be thinkin an inside mixture/temp flap problem...only Vagcom diagnostic (or total disassemble) will tell.

 

you need to run basic setting in the a/c. sounds like the compressor is fine as well the amount of freon.
one of the flaps is allowing warm air from the heater core to get thru.