1998 with 5.9 Not getting up to temp
#23
Also, how cold was it out when you tried all this? That can make a huge difference. Today it's about -11 here. I drove my truck around town for a couple of hours with my radiator completely blocked off (which I normally do when it's this cold), and it never got over about 180ish. If I did that on a 30 degree day, I would eventually overheat it. Outside temp is a biggie.
#25
this hasnt been asked, and dont remember reading it......is the coolant full? did you burp the system the right way?
Also, how cold was it out when you tried all this?
doing the 'block' on your rad, and after running the truck for a few miles, I'd venture to say it's impossible that your engine would run so cool.. I second the IR temp sensor idea, just to use yet another temp sensor of some sort OTHER than your gauges temp sensor.. I'm still thinking it's that sensor though.. You should give it a shot- they aren't that expensive.