My 1982 380 SEL is overheating. The wierd thing is that it only overheats when I push the engine going up a long steep hill to my home. Othewise the temp gauge hovers just under the 100 degrees level.

So while driving around the city, the engine temp is fine. But when I go up the mountain to my home, the temp rises and the car over heats.

I changed the thermometer this weekend and it didn't make a difference. I don't lose any fluid unless it over heats. I checked the fan and it is running when the engine is at running temp.

Any suggestions?

Many thanks for your help....