Chrysler Repair: 96 Chysler LHS 3.5 Overheating!, chysler, guage

Question
This has been an ongoing problem. The temperature will be steady for 30-45 min and then rise sharply and VERY quickly to the point of overheating. I have changed the resevoir, water pump (boy was that fun), i have pulled out the thermostat all together, i have checked the relays, the fans are working, and i changed the little thermo guage thing sticking up like a spark plug right beside the hose where the thermostat is located. I am at a loss at this point. I can let it idle with no problems for up to an hour.... but then take it on the road and it overheats. Please help!

Answer
Hi Bryan,
Have you put a light behind the radiator to check for whether the fins may be clogged with leaves or dirt? Have you done a cooling system flush with heavy duty cleaner? Is the left side manifold of the radiator hot? You may have impeded flow of air or coolant at the radiator proper.
Roland