fan problem

In the summer or during warm weather....l turn on the air conditioning and l can hear a loud squeaky noise....its stops once l have finished accerlrating past 60 km....it also stops when l use the ECON for the climate control...what could be the cause of this squeaking....and how could l fix it...

Does it sound like it is coming from the front of the car? If so, it is most likely the tensioner pulley for the A/C condenser. They are crap on the A4 and always go out. You can rebuild them, but usually it is just easier to buy a new one. They are a snap to replace also. Othertimes it is as simple as needing to tighten up the AC belt. If those aren't it, occasionally on Audi's it's the actual AC condenser clutch itself, and that is expensive to fix.
Good Luck with it

Thanks For The Advice...when I'm Driving It Seems The Sound Is Coming From The Side Of The Car....underneath...i'll Check That Stuff Out