I really like Dr. House. You at least stated the year make and model, but you failed to state where in the world you are. Believe me it can be an important piece of information for a proper diagnosis. Without that info and with the info you provided, I think you have a restricted radiator. I know. You just replaced it. Take it for a drive and check the whole back of the radiator with your hand for cool spots with the engine off of course. You didn't say the car rons hot at highway speeds or climbing which could be symptoms of a headgasket problem.

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