Check this one out, my 85 toyota 22re has a new engine with a new rad,thermo stat,water pump. runs great idlse all day and around town no problems but as soon as i get on the high way at 70 it will over heat, guage goes up but never seem to boil over, I drove with the guage in the red and though for sure it was going to blow. once you slow down from the high way it cools down. poor truck just hates to go fast <img src="/forums/images/graemlins/lol.gif" alt="" /> So what could be wrong, I used a 22r block and I dont think i put a temp sending unit in?? were should it be? also could the fan clutch be slipping at high speeds but then i would think the air moving through would keep it cool anough. anyone have any ideas? I drive 65 mile one way and really need this thing fixed.
thanks

Did you put new radiator hoses on when you did all this work. Old hoses can and will collapse at high speeds blocking coolant flow..

High speeds on the highway....so air flow is not an issue(no mud in the fins?).
That means you have a water flow issue. You need ANOTHER radiator

no i did not change the hoses, when it was hot i felt the hoses and they seemed really soft, i would think with the thermosate out they would be hard with the water pump pumping. the hoses are really soft and could probably be changed.

Rob-

Put a thermostat in there while you're at it.

No thermostat, and the coolant can flow too fast through the system causing greater heat retention.

i think your problem is your hose, you said it was soft when it was hot. i think i would be likely that the hose would collapse at high speed.

I just had a very similar problem. I just put all my 22re stuff onto a good 22r I got from a junk yard, put a new waterpump and thermostat in, and changed all the hoses. I used my old radiator because it was still working well when i pulled my old engine. I drove my truck around town for a day or two, and it ran fine. The first time I went on the highway it over heated, I used a radiator flush, and ran it for a bit, drained the system, and when i did I saw a bunch of rust and scale come out of the engine block's coolant hole, but not out of the bottom of the radiator. I took out my radiator, and shook it a bit, and heard a bunch of stuff shaking around in there. I tried to flush out the radiator by itself, by filling it half way up shaking it up and draining it. I got a lot of stuff out, but couldnt get it all out, and ended up breaking off one of the side mounts in the process. So I got a new radiator, put it in, and it has been running cool at any speed on the highway ever since.

thanks for all the help, I got a new top hose today, the bottom hose seems to be hard to find for a truck with out power steering, I have the one peace hose and everyone has a two piece hose set. on my bottom hose there is alot of bends in the hose and it is soft should there be a stiffness spring inside the hose?
I also ran the hose through the new rad and it flows great and the block flows nice also, what about a fan cluch slipping at high speeds?

At highway speeds, the fan doesn't matter. You could take the fan out and run highway speeds all day long if your system is working correctly.

Went through this with my 82, tried everything and finally fixed with a new radiator.