Before tearing into the cooling system. Get a laser thermometer and check the radiator. I've found mine to be partially plugged, and will be replacing it. With the needle at 105c on the guage, the thermometer was showing 110 - 115f across most of the front, and around 140 - 150f on the back. The tech that I was watching use this was also able to verify that the water pump was indeed circulating, and that the thermostat was opening by checking temperature all along the engine and external plumbing. It's a neat tool that will be added to my selection very soon.