DoubleNutz

Yea, I think you are correct Bill. The temp guage always read what I thought was a bit high although that is normal in the 89+ years. Then I lost my radiator hose clamp while driving on a 90degree day recently. When I repalced the lost coolant with water (because that was all I had available at the time) the temp dropped considerably. When I flushed the entire coolant system (it is very clean no issues there, remember this is only 70K miler and they are well maintained miles) and replaced the coolant the temp shot up to right over the 3/4 mark instead of just behind it.

I have to believe that coolant, while a good thing for lubrcation and antifreeze, is not much of a coolant at all when too much is used. Gotta believe that Flott Leben has it correct here.