Over heating prob. ideas coments please

[816allen]

When i took her to get legal maybe 10-15 min away jumped on highway most of the way jumped off drove maybe 5 min and she did great once i left, went straight on the highway maybe 5 min she jumped up to 230 240
Jumped off real fast turned it off.........
Cooled down drove home flushed entire system, everything and put new 180 stat in and new antifreeze of-course .
Now i drive it on the highway maybe 2-3 min and shes doing it again wtf hoses all have springs in them so they cant collapse water pump aent leaking but do ya think its going out.....?
Rad looks great...



Also I turn on the heater/defroster i guess, just a slight hint of heat coming out.
I'm also not really feeling a good wind from it or the fan below or on top is that normal?
I know shes old but ya never know so I'm asking,I tried search but really didn't get answers like i want...
Please any info or ideas ya got would help me out thanks!

Also I did burp her real good so i doubt it has air in it...

[Eagar1]

Could be lots of things, what engine? How old?
I have actually seen impellars rusted away so bad they didnt pump, and the pump didn't leak, you could have an impellar spinning on the shaft. You could have total blockage in your radiator, block or even heads.
Pics help too =)

[816allen]

Sorry my bad heads been worked before i bought ....I was told and have no proof....
Its a 250 Straight six not sure what year because it has a egr on it so I'm thinking it was out a new model than my truck mine is a 65

[816allen]

I dont have any new pics but here is some when i got the truck...

[Eagar1]

The EGR may be your problem, as if it is not set up properly it can lean out the engine causing it to run hot, especially if your carb isn't set up right already, and you could have the timing off, etc etc.

You may also have a blown head gasket, which you can check by leaving the radiator cap off while the truck heats up and see if you can see bubbles, or you can even get a tool that can sense exhaust gas that you hook to the radiator.

You can even have a cracked block but that usually puts water in the oil.
If the engine is well worn, or has been over bored, the cylinder walls can be too thin, and the water heats up faster than the cooling system can handle.

If the head was worked on they could have not installed the right head gasket, or put it on wrong blocking the proper flow of coolant.

Just some other points to ponder.....

[816allen]

Well today I burped it again and once it got to about 210 215 it stopped bubbling and was starting to just rumble out the hotter she got...
I have the right intake for it i guess ill get some gaskets for it and carb and slap it on see if that helps man I hope it aent a blown head gasket never changed one and not sure if i want to or if its worth it....
Wouldn't it smoke at all with a blown head?
Also carb needs to be replaced or rebuilt its loading up if i floor it...
"not in gear "

[Chevy Fleetside]

Looks like it has a new sender on it. if so they don't work with the older trucks. Mine did that with the new 350 and new radiator. I wold make it get hot and somehow open the cap very careful like. I guess I have had lots of practice on it and can do it somehow. I was able to put a thermoter in the radiator to find out it was fine. I put a resister on the wire so the gauge and sender would be on the same page. Even if you go get a cheap gauge and hook that up just to make sure.
The only other thing I can think it would be is the radiator. If the core is clogged up it will be fine on the streets but as soon as you get on the freeway the temp will rise fast. No amount of flushing will cure that that I know of.

You could also get one of these

[Frizzle Fry]

Only overheating on the freeway sounds like timing too advanced to me. If you are cruising at hwy speed and step on it do you hear pinging? Also you say you get a stumble when you step on it "not in gear." This could indicate an overall lean condition which would will contribute to overheating. It could also just be a bad/insufficient accelerator pump squirt.

[Frizzle Fry]

BTW, I did a head gasket on my 230 in an afternoon by myself. No big deal. Also, it is possible to have a blown head gasket without a coolant leak on these. I replaced mine for a compression leak. But it didn't cause overherheating...