this is like deja vu.i just had the same issue.t-stat failed,replaced it and it was bad out of the box.replaced water pump in hopes lol and still the same.another t-stat and all is good.
least it helped me see my digital gauges where not worth their salt.close enough to know something was up,but not much better than stock gauge really.only ballpark.so i replaced with auto meters after too and now i know exact readings at all times.
start with a good gauge.do yourself a favor.it'll save ya some $.

oh yeah,and you shouldn't be able to squeeze your bottom hose because there's supposed to be a spring in that one.

radiators.a lot like the aluminum ones.
i went with the copper/brass;
https://www.ford-trucks.com/forums/9...l#post10513622

don't do anything until you get a real gauge or a point n shoot thermometer at least.

oh yeah,and cheer up.no matter what happens it could always be worse:
Dealer want $2,200 to replace my radiator
that's the 6.4l's common problem,like air intrusion is ours fyi(well ok,maybe its actually "growing oil",but it's right up as very common nonetheless.)
whenever you get down,and think working on old Betsey is starting to get old,it's threads in other diesel sections that always brings a smile back to my face,and im over it real quick haha.

 

ha ha ha thanks for that. and well i tested my old therm which was an after market one and it opens good just seems to take AGES for it to open. but i suppose that is how its supposed to be so my only guess after that is that it would be a water pump

 

you have to use the motorcraft t-stat #rt1049

reason explained here:
https://www.ford-trucks.com/forums/1...ght=thermostat

 

okay i read this and as wierd as this is........... the ford thermastat and the after market one i got are one in the same and very identical to each other. the one in the picture on that link looks nothing to the ones that i have. the only difference is that on this after market one is that it has a bleeder hole in it but it does not open when water is flowing threw it or when it is closed and the motor is running. if the motor is off then it will open allowing little bit threw but not alot. im assuming that this is for the simple fact of it bleeding out air in the motor maybe idk. but the both of them are the same exact ones only diff is the aftermarket is made in china idk bout the ford one lol

 

okay guys.

After further inspection of this issue that we all seem to have here. I had gotten a wild hair up my *** tonight and decided to pull my water pump. Why would i do such a thing? Well because i was convinced that my water pump was not working properly. So here is what i have come up with.

I pulled the water pump Praying that i really didnt have to buy a new one and well i guess my prayers came true. My water pump is in good working condition and after cleaning the dirty bish, i came to realize either this pump is brand new or it is still the stock one and the PO of this motor did great care in the motor.

So while and during this escapade i decided to also check my thermastat. Upon which i had discovered one small issue with out systems. I did not decide to test it via a pot of boiling water, i more simply opted for the lighter, in which it does open just not all that fast. Opens probably about as fast as a snail moves. So then i got curious. To my curiousity i opened my thermastat all the way open and then decided to try and put it back in its hole! IT DOESNT FIT! I have come to discover that when our thermastats open they will not open fully. This gravely concerns me. This is the only thing keeping our motors cool and it doesnt open fully. So what is it that we do about it. WELL i have a grinder and when i get done being irritated that i now have to buy a new water pump gasket, i shall report back and let you know what i discover or "modify" .

Good night Gents and Ladies.

Mikey OUT

 

Seems some folks have to attend the school of hard knocks. Glad you found the issue, testing a thermostat with a lighter? Pot of boiling water!! Test it the same way it gets used!!

Let us know how you make out fixing it. Majority of the time overheating on these trucks is one of two things, poor thermostat, or a bad fan clutch. However, it's easy enough to check rad flow, water pump flow etc, for little to no cost, so try them in the process of diagnosing the issue.

 

well i prefer to do the hard knocks deal because then you can actually see what is the problem and on top of that i needed to clean up the pump anways and it could be a bad fan clutch too i never thought of that but at least i know everything works. and it was midnight when i got everything out. so i dont think my parents would have liked it if i were in the house at midnight boiling water lol

 

Ummm I don't know what you think testing it with a lighter will do....
Yes it will tell you if it opens or not, but it WILL NOT tell you WHEN it opens. I could use a lighter to "open" a thermostat thats set for 250 degrees, it will open, but it will also overheat and destroy the engine... I could also use that same lighter on a thermostat that opens at 150 degrees and it will open, but the engine will never get to peak operating temperature.

You need to test the thermostat will a pot of water. Stick a thermometer (cooking type works great) in the water, and heat up the water until its close to boiling. Then slowly increase the temp while watching the thermometer and the thermostat. Figure out at what temperature the thermostat starts opening, and when it fully opens.

I bet you this will take you less time than you've spent reading and replying to this thread and running around in circles.

 

But I like running in circles lol I don't have a cooking thermometer so that's out but i got ecrrything back togethrr and it works fine now that tge thermastat opens fully . I ended up cutting out about a half an inch of the bottom of it and allowed it to ooen fully and tgen rotated it till it deopped in works great and sotty about tge typos today my phone is a giant pile for some reasonu