Hellooo. On my Vauxhall Velox (straight 6, 3 speed manual) there wasn't a thermostat fitted when I got the car and I'm not too keen on running without so I fitted one. Well, 3 to be exact (one after another, not all at the same time) I know 2 of them were good ones. Anyway; what happens when I fit one is the gauge goes to hot (maximum) after a very short distance and stays there. 1/4 of a mile, if that. I know it can't boil over after the distance travelled but, I don't like it so I continue to run without one. I'd rather not so, any ideas as to why it should go to hot that quick?
P.S. When I run without one it stays just above the rest stop and stays there.