Temp guage being weird
My temp guage when normal sits right below the middle line. Whenever I don't give it hours to cool off in between stopping and starting again the guage will cover the middle line or go slightly above it but never higher than that. It always goes enough to make me nervous. Or when I drive on the highway at 70mph for an hour and have to sit in 35mph traffic and at red lights it will start to do it also. My coolant tank has been replaced because there were cracks in it and coolant has been flushed as well. Things to check?