2008 avant water temp switch

hi i have 2008 s6 avant 5,2 my dash says its hot even on start up so its cold drive it temp goes up to 90 no problems dash flashing constantly so hoping it temperature switch but was wondering its location so i could replace it but was having trouble finding it if anyone could help
Thanks

Its on the coolant pipe connecting two heads, on the firewall side of the engine

cheers will have look for it there thanks