audi s8 1999 aqu engine code 360bhp overheating problem

[az786]

hi,i have a 1999 s8, sorry the engine code is AQH NOT AQU! The temp guage sits at 90 then rises to 100 then back down but just goes up and down from 95 to 100. I have replaced the viscous fan, did the carrot test and the fan just stopped, Replaced it with a new item from euro carparts, replaced the electric fan as this wasnt working at all, audi replaced the timing belt,waterpump and thermostat etc 2 years ago at 120k, mileage now showing 155k.The electric fan works when the ac is switched on, but when the heaters are on the fan kicks in, but if i turn the heaters off the fan turns off is this right? im not sure what else to check now but im assuming maybe my waterpump could be gone.

any help appriciated

thanks

Edited April 3, 2009 by az786