The temp gauge on my 97 4.6 is maxed out all the time. What would cause this? Doesn't matter if the truck has been running for an hour or sitting for a day. Once I turn the truck on it buries the needle and doesn't move.

 

Have you replaced the coolant temp. sending unit yet? I've always had the problem in my Fords where the guage would never come off of cold, changing that always fixed it.

 

I will look into the coolant temp sending unit. Mine shows its maxed out hot.

 

Also, I'm not sure if its the same with these trucks, but on older Fords, they have a sending unit for the computer to adjust for fuel mixture, and another for the temp. gauge; make sure you get the one for the gauge.