The Body Control Unit failed to send signal to radiator fans to turn on within temp range. The BCM is not really expensive itself, but it needs to be programed or re-programed. However only the dealer can do that, so you end ups paying the full amount the dealer used to charge....think about it.

This is my daughter's car. She is 22 and drives her car a lot going between two jobs. She is losing antifreeze somewhere, but it is not leaking anywhere. We have changed the thermostat and have also purchased a new water pump, but are not sure that is the problem. We fill the antifreeze when she is ready to leave the house and in less than a 2-5 drive, the temperature on her dashboard will read in the 240-260 range. If she plays with the heater it will go up and down, but will not cool down.

THESE CARS HAVE A SERIOUS PROBLEM BEGINNING WITH THE 2001 MODEL YEAR! THE 3.8L ENGINE SHOULD BE RECALLED FOR THE UPPER INTAKE MANIFOLD, I AM A MECHANIC WHO WORKS ON A FLEET OF THESE IMPALA'S. WHEN YOU HAVE TO REPLACE UPPER INTAKE MANIFOLDS ON A REGULAR BASIS SOMETHING NEEDS TO BE ADDRESSED BY GM!!!

this gauge problem is a pain. now never knowing if it is overheating i replaced thermostat, flushed, new hoses. did not help. Due to previously owning a 1988 chevy dualle from new it had same problem, It was the gauges as well. I had to replace entire cluster at cost of over $900.00. five years latter,same prob. looks like impala following dualle tire marks.lol, not