So, this new 300SD of mine wants to overheat, though only at idle.. As soon as im moving the temp goes back down to around 80c. The moment I stop though, the temp starts to rise, (I just make sure im not stopped for very long). At first I suspected the fan clutch however, as I decended a long steep hill I decided to put the car in neutral. I was going 45 and the temps started to rise like when it does when im stopped..

Thermostat maybe?

Thanks for all your help

Aaron

 

crap.
are those expensive / hard to replace..?