Steve, When u turn the ignition on does it straight away shootup to the top of the guage and stay there? If so then I think u have the temp guage sender not connected right, i know when we were sorting my over heating probs out we could test the guage was working by putting a screwdriver in the sender and it would send the guage up and down just to test it. Dunno if yours would be the same thing ? lol dont want it running inthe red m8!! Mine dont go over 1/4 at the mo