I forgot to add:

I bled the system by starting the engine cold with the reservoir cap off and running it at operating temp. a while, let me know if this is wrong, it's what I read on some threads. The car is a 300cd turbo. I'd love it to be an air pocket.

I don't think the aux. fan is coming on at 100C, but I'd have to check further to be sure. I know at least it was working some 6months ago.

Will 100C (if it is in fact at that temp) hurt the engine, or is that within the acceptable range for very temporarily?