antifreeze for type44

[Ameer Antar]

there are all kinds of antifreeze out there that are s'posed to be for our 
Audi's, like blue, pink, even orange now...I flushed my system this summer 
and replaced the green stuff w/ pink Pentosin from Blau. I back flushed the 
radiator and block very thoroughly. But then my radiator fan started doing 
weird things. It would run constantly w/ the engine off or on, which would 
make the engine run too cold on the highway. I did some investigating and 
the wiring turned out to be perfect, so I figured it was the sensor for the 
rad. fan. When you disconnected the harness from the sensor the fan turned 
off, so it must have been in the sensor. So I think the stuff I put in 
affected the sensor. What do you guys think? What antifreeze is good for 
stock audi radiators? Thanks.

-ameer
'84 5kT