New owner of 74 CJ5

Hi all,

On October 15, I became the proud new owner of a '74 CJ5. I bought it at an auction so I figured something had to be wrong with it. The body is excellent, frame appears to be solid, and it has a new Bestop soft top. Also has Hedman headers, Holley 2 bbl carb, Offenhauser intake; straight six (232), 3 speed trans, etc. It starts and runs fine - no noises, knocks, etc. However...

I changed the antifreeze and was warming it up to change the oil. The radiator cap was off and when the thermostat opened (I'm assuming that's when things started) the antifreeze started overflowing the filler neck. Not just a little but it looked like a small waterfall
(antifreeze fall?). It was a smooth overflow instead of the antifreeze being blasted out (like my first flathead Ford did back in the dark ages when it developed a few cracks in the block), but it was coming out pretty fast. I didn't investigate further - just changed the oil, added more antifreeze, and replaced the radiator cap. Buttoned it up for the winter and left it until next spring (I'm in Texas and the jeep is in Colorado - I already miss having it around to mess with).

I figured it is either 1) plugged radiator, 2) blown head gasket, 3) cracked head, or 4) cracked block. Some suggestions by other jeep owners are less drastic and I'm hoping they are correct. These include air getting into the block when I drained the antifreeze and/or a thermostat installed upside down so the air can't escape. Any other ideas as to what it could be? I'd like to take back the necessary repair parts next spring if I can.

Thanks for any help/advice anyone can give. I'll admit to knowing almost zilch about the specifics of my jeep but I'm learning, thanks to these jeep forums, repair manuals, etc. I've already discovered that you folks out there are a mountain of info. Good stuff!

I'm not planning to do much to it but enjoy. It's gonna be a fine sidekick up there in the mountains.

Thankie for any info, advice, etc. you can share.

 

Welcome, you could just remove the thermostat and warm it back up. that should tell you if it was in backwards. sometimes when replacing the anti freeze you can get an air pocket in the block with the thermostat closed. I drill an 1/8th inch hole in the thermostat before installing. This allows the air to excape. Walt

 

welcome from massachusetts, I bought a great pair of clamps that you could sinch the upper hose and remove w/o loosing to much anti freeze. look down the throat,I've never seen the inside of a 232 but I can't imagine the spring side facing the radiator.The worst vehicles to get air bound are the imports w/ a sealed cooling system(but who cares about them here).Only trick I've done was to fill the block when raplacing the thermastat. that was on a amc 304 w/ the housing on top.again not familar w/232.

 

Thanks guys. Air in the block and the thermostat position are the first things I'm going to check when I get back up there.