OK this is driving me nuts! Shop just put in my 3.1 stroker and the temp gage pegs as it warms up from a cold start. It may take it 1 to 3 minutes before it drops and after that it is fine all day long until you let it cool down completely.
I don't like this!
I have removed the radiator cap until operating temperature is reached, topped off the syatem at the thermostat housing, attempted to get the upper engine hose free of air etc. If I pull out the thermostat it does not do this. Yeah I thought I had a bad one although it was brand new and replaced it only to have the same problem.
Someone set me straight!!!