I second what Phil said. I would say that you have trapped air in the cooling system and therefore getting the high temperature. With the engine being cold I recommend you slacken off the hose clamps on the top rad hose. Remove the hose at the end pointing to the engine, twist it around a bit and fill the rad, then do the same with other end of the hose get coolant into the engine. Install the hose and tighten the clamps. Remove the cap from the coolant reservoir and start the engine and let it idle. Watch the temp gauge and also the resevoir.
At one point you will most likely see air burbing out. After this put the cap back one and take the car for a test drive. If everything is normal temp. should be about 80 Degr. F. All this with the thermostat in place. This procedure worked for me on 2.5 liter diesel non-turbo.