I have an overheating problem on my '83 944 and not quite sure why. On short trips the temp gauge pretty much always gets up to the yellow line at the far right. On longer trips it will go all the way through the yellow. My mechanic told me that he didn't think it was much, and he put in a temp. switch to turn the fan on at lower tempurature, but it still overheats. Since the fan turns on, I assume that the thermostat works. If anyone has an idea what might be causing this..shoot me a line.

 

I'm not completely sure since I have an 88 944, but isn't the thermostat a different thing that the thermofan switch that controls the fans? Maybe you have a bad thermostat, since that controls the flow of coolant from the radiator to the block. The temperature guage sensor is mounted on the block and reads that temp, not the temp of the radiator per se.