92 FJ80 Cooling problem

[vrover]

Hi,

We just got a 92 FJ80 with about 180Kmi. Going up and over the Rockies we noticed that the coolant temp went way down and there was not much heat coming out
of the heating system. We stopped in Golden and had it looked at - the thermostat was stuck wide open. SO, new thermostat. But, guess what? The problem still
seems to be there. At idle, then temp gauge sits about right but if we drive around, it goes back down to cold. Now, it IS cold (about 4 degrees) but the thermostat
should always keep the engine at operating temp. That is what it is there for.

Did the mechanic check the new thermostat? No. But I saw it come out of new part box and get installed.

Any ideas?

Thanks!!

 

[MoGas]

Stuck fan clutch? Did it ever work after the new thermostat was installed?

 

[60Dan]

Was the thermostat installed the right way up?

 

[60Dan]

Edit: I don't know if it's physically possible on an 80 series to have it in upside down, but I saw it happen once on a Honda. Doesn't cost anything to check