I just recently purchased a great used 92 F150 4x4 4.9 300 pickup.
I notice that the temp goes up to the very left edge in normal. Thinking that the sending unit was bad, I replaced it and another sensor that supposedly was for the computer. This one is located on the thermostat housing. I found no difference in the gauge reading. Thinking it may be the gauge, is it possible to remove the water temperature sending unit and replace it with a mechanical water temperature gauge like Sunpro?
I haven't noticed any loss in water or any overheating but, I've never had a vehicle that ran so cool so, this is why I wanted to put in another gauge. Or is this normal for this engine? Any feedback would be appreciated.

 

Ok...first, have u changed the thermostat? It may be stuck open, thus allowing a constant flow of coolant. This will cause the engine to run cool. If you haven't changed it, do so. However, bench test the new one with a pot of water on the stove and a candy thermometer making sure it opens at it's designated temp. this might help....

 

I also have the same issue with my 1994 F-150 2 wheeler. I have tried the usual, swap the parts unitl it gets better but, haven't corrected it yet. I have changed the following: Thermostat 195 deg. F. (twice), heater core, water pump, heater hose, radiator hoses, flushed and install new coolant. I wonder if the radiator or block is plugged somewhere. I bought the truck new in 1994 and just this last fall noticed the problem. I don't have a problem changing the radiator but, don't want to spend the money if the block is plugged somewhere. I sure could use some advise on this one!!!
Thanks
Trucks4me