I have a freshly rebuilt 22re in my pickup so no head gasket issue but the problem im having is that the truck normally runs at about 1/8 to 1/4 on the temp guage and now when under load its (up hill (fairly steep) at speed, at least 40 mph the temp guage is going up to the 1/2 way mark) Would a clogged cat cause this or should i be looking at the rad? I know the previous owner replaced the rad about 2 years ago and he used stop leak to try and fix the head gasket.....

After the hill that makes the temp go up, as im going down or staying on a level stretch the temp goes back to normal and stays there.

Thanks for any insight.

 

1/2 is perfectly fine. Both my '93 and '95 have/do run at just below the half mark with no problems, my '88 ran at like 1/3 and would sometimes do what you describe, but thats because it had a 180* thermo in the winter (-50F )
Its normal for a vehicle to increase temp when going up a hill, it has to work more! What temp of thermostat are you running now? I'm guessing 180*

It wouldnt hurt to flush the radiator.....

 

Yeah im using the 180 T-stat. It has never went over the 1/2 mark, and i dont want it to LOL. Just being paranoid.

 

Clogged radiator, most likely. When was the water pump last replaced?