I just had a new t-stat and water pump put on my SD and now the temp goes up to about 100 (or is that line 90?- the one between 80 and 120) whenever I get up to highway speeds. Around town it's a little above 80 which is where I expect it to be. I checked the coolant levels and topped them off but there may still be an air bubble. But i don't see how that could affect it only at certain speeds. If it was a fan issue the temp rise would be reversed so I'm at a loss. Didn't find anything in a search either so hopefully someone here can help. Thanks.

John

'80 500SE AMG (yes, it's a real one)
'80 300SD