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Discussion Starter · #1 ·
I've ran out of ideas. Now I'm asking for help. I have a freshly rebuilt 454 with stock bore. I cant get it to stop overheating. Its running at like 240. I've retarded the timing, put a new aluminum radiaitor in, new water pump. no thermostat just a restrictor plate. several different electric fans, I even put a flex fan on. I tried a different guage and it reads the same. Its in a cj5, I have a one pice front end and it still runs hot with the front end off. This is my last hope. I'm going to take the heads back off and insure that I didnt screw up putting the head gaskets on. Any ideas would be greatly appreciated.

Tom
 

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It will run hot if its too retarted as well.....have you thrown a light on it? Also, I would put a 185 or 190 thermostat in it and see if you can atleast keep it under 200, its cheap and easy.

Mark IV block and heads? Are you pretty confident that you used Mark IV or VI gaskets?
 

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I doubt its head gaskets.

heres a list of things to start with

1. antifreeze, check it with a tester and make sure its not stronger then -30*. if its stronger then that it will be to rich to suck out heat, antifreeze needs a balence of water to work. if its pure the stuff will not remove heat and the gauge will peg.

2. where are you taking the temp gauge reading. if its in the head it could be off. take it fom the top of the intake if its now in the head.

3. if you have reused an old water pump then you may have the problem I have run into in the past. the impellers are stamped steel. they rot. when they do rot the fins that move water rot off. if its an old pump remove it and pop the back cover, if theres no paddle flanges on the disc you found the problem.

let me know what you find.
 

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Discussion Starter · #5 ·
I doubt its head gaskets.

heres a list of things to start with

1. antifreeze, check it with a tester and make sure its not stronger then -30*. if its stronger then that it will be to rich to suck out heat, antifreeze needs a balence of water to work. if its pure the stuff will not remove heat and the gauge will peg.

2. where are you taking the temp gauge reading. if its in the head it could be off. take it fom the top of the intake if its now in the head.

3. if you have reused an old water pump then you may have the problem I have run into in the past. the impellers are stamped steel. they rot. when they do rot the fins that move water rot off. if its an old pump remove it and pop the back cover, if theres no paddle flanges on the disc you found the problem.

let me know what you find.


I started out taking it from the head. I moved it to the intake. It is still reading the same.


I put a new water pump on when I rebuilt the motor.

I've done probably 15 things to it in an effort to get it to cool off. nothing I've done has had any affect. It still heats up just as fast as the day I started out with an old crapy Jeep radiator. It takes about 5 minutes and its hitting 230. Thats at an idle or 4000rpm's Its all the same amount of time.

Thanks.
 

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Hmm. I swear it sounds like your not moving coolant. you aren't colapsing the lower hose are you? if its not a wire reinforced one it will suck shut and prevent the coolant from moving.

have you pulled the upper hose and just let the garden hose run to see how well it flows through the radiator to the T stat housing? if you arn't flowing there you have problems somewhere.
 

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Discussion Starter · #7 ·
have you pulled the upper hose and just let the garden hose run to see how well it flows through the radiator to the T stat housing? if you arn't flowing there you have problems somewhere.[/QUOTE]

Not sure what you mean? but no I havent. please explain.


Bottom hose isnt sucking in. Its a mind bender isnt it:confused: I'm about ready to fix it with my ak47:naughty:
 

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if you have the restrictor plate T stat then remove the upper hose from the housing. shove a tennis ball in the hose to block it. then use a garden hose to flow water through the block to the heads and out the T stat housing. this is the way the drag race guys did/do cool down on stock class cars.
if the water isn't pouring out as fast you can put it in then you have to find out why.
 

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Discussion Starter · #10 ·
I'm pretty sure the ports are clean It was just hot tanked and cleaned. I was just looking for some ideas before I took the heads off. It looks like that's what I'll be doing. I just hope its the gasket.
 
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