so the truck runs between normal and 3/4 of the way up the temperature gauge and goes into red after a while.
ive replaced the temperature sensor, the thermostat a new radiator and a new electric fan.

 

Try the Carb thermostat. It opens at 180 instead of 195.

Otherwise, i'd check out your fan clutch and then check the flow of your radiator.

 

he said he has a new electric fan si i sur he knows its workin an has a new rad but should prob still check flow. and what about water pump?

 

Check the water pump and the timing belt. I was running warm when the timing belt began slipping over the water pump pulley and not turning the WP at peak efficiency.

Is your head gasket in the early stages of going and leaking exhaust gases into the coolant, thus heating the coolant to abnormally high temps?

 

May be a long shot. But for me it was i tiny little hole in one of the freeze plugs. Replaced it and no more heating issues. Just look for liquid/vapor around that area.

 

oh its got a v6. disregard what i said, then.

 

i forgot about the water pump, and ya i think thats what it is, because there is now a knocking grinding noise coming from that area and i think that barings in the pump are out.

 

If you do the water pump, also do the timing belt, the idler pulleys if they have lots of miles on them, and the TB tensioner.

 

Have you bleed the air out of the system? Mine had the same problem, and it took me 4 tries to get all the air out of it. Once I did, my gauge went to 1/2 or lower, depending on driving speeds.
There are several write ups on here - search "burp"

 

Does it overheat on the freeway?