I have a 99 buick century. I just recently did an headgasket change on the car. But whenever I drive the car and stop at a light too long, the temperature gauge keeps on going pass the half-way mark and then falls back down to normal operating temperature. I''ve check the oil and coolant and everything I could think of.But everything still seems fine. So I was wondering if it''s normal or could it be anything else. If I can get any help, I would appreciate it. Thank you.