No, didn't test the thermostat before putting it in. I have never had a bad thermostat. It's a bugger to get to. It's probably just air in the system, but don't know how to get it out. Should I fill the radiator all the way up to overflowing or what? I'm at a loss.

 

did you put in a new t stat? if so is it possible you put it in upside down. Not calling you out like your an idiot but I know some ppl that have done it by accident

 

That does happen.

The engine shouldn't get that warm that fast- unless its dang near empty.

Leave the rad cap off, idle engine, pour in juice. Fill it to top, wait a few seconds and repeat. When it holds steady slightly rev engine, and do it some more.

Is your top hose under pressure at all?

 

I made sure I put it in the exact way it came out. Yes, it is new.

 

I haven't checked the top hose, but will. I have no more antifreeze. I put 1.5 gallons in; that's all I had. It was a 50/50 mix. Adding water will dilute the mixture; is this okay?

 

So long as it doesn't freeze you're good with water, but I wouldn't leave it in there long. It'll certainly get you to the shop where more coolant lives.
Add the h2o and see if your over heating stops.

 

I found a DIY on burping the coolant system. I'm going to follow these steps and see what happens. Wish me luck. I will update either way . . .

 

just do the burping method and turn your heat on high that seems to help me out then I can tell when the heat gets hot I know its good

 

Alright; it seems I made a little headway. The temperature gauge is at 230 or right between 200 and 260. It's not going past that. I drove it down the road a mile and it didn't go past that point. Any other ideas?

 

I installee a 180 stat when I did my plenum fix. I never see the temp gauge touch 200, it runs at 170 180 I have efans also. But as far as your truck I would just let it idle and rev it up a little. use a glove and grab the thermostat hose and see if its still stiff if so then its the t stat


Before I did my plenum fix with stock t stat I was running about 220 230. For some odd reason these trucks like to run hot