I have a 99 SE automatic 65k miles.

During hot weather, the Temp gauge will go up to the "H" after driving on the highway for 20 - 30 minutes. On cooler days, the temp gauge stays at its normal position mid way between C and H

The thermostat has been changed, and the coolant has been changed and flushed at 30K and 60 K

The dealer checked the thermostat, water pump and sensor operation and could not find anything. They are now suggesting that the radiator may be plugged. I think it seems a little early for a plugged rad

Has anyone had problems with their rad or any suggestions?

Thanks for your input