I have watched my Aux fan go into 'oh ****' mode, I am pretty sure it kicks in around 110C
I cant think of any other good explanation why the temp quickly goes back down after hitting 110C
Also I am confident I confirmed my viscous clutch is not engaging, I suspect this is the combination which sends the car on a overheat cycle in warm traffic, when outside temps are around 27C and above.
My thermostat is fairly new Audi original. Belt changed by pros
