My CJ has a recently rebuilt engine and also a new radiator, whats going on is the cap is not sealing on the rad neck. The bigger issue is with coolant about an inch below the top of the neck coolant is being pushed out of the radiator and continues to do so until right below the top of the top of tubes. The coolant is full of bubbles and when reving the engine will come out of top of radiator
There is no white or blue smoke coming from exhaust, engine oil has no water in it, spark plugs look good, engine runs good, compression is 130 in all cylinders
I cannot get my radiator tester using the adapter to seal so I cant pump up system. Im at the point im going to drain coolant remove rad and hook up something to pressurise the block and see if will maintain some pressure
Im thinking the head has a crack or the head gasket in one cylinder is leaking compression into cooling chamber
Any thoughts/ advise are greatly appreciated as im bummed out of this
Steve, when you say bubbles what are you seeing? Large burps or small and many? If you are leaking water into the motor or out of the motor you will eventually see it show up in the oil, exhaust or floor. The radiator does not fill to the top. It should be about an inch down. You need room in the radiator for the water to expand when it heats up.
What head gaskets did you use? Did you re-torque the studs after a heat cycle?
I agree with your approach. Find a way to pressurize it, or see if you can fix the pressure checker and find out for sure.
Small and many bubbles, so much so I cant see the coolant
The head was already on when I got the engine back as I had the rebuilder assemble the engine
Im going to check all the head bolts asap. I have to put some air pressure into block, years back I had my 383 ready to be dropped in the car and started. Before I put the engine in I rigged something up and put some lower pressure air into cooling system. To my surprise it wouldn't hold anything, than I noticed a hissing noise, one of the heads was cracked
Either way I will get to the bottom of the issue, Thanks for advise
It is concerning that it wants a lot more room and is pushing the water that hard. If it was full of air, it will push the water out until the air is cleared from the motor and hoses.
I think it is much easier to find the leak and to pressure check the system if it is full of water. The pressure will come up much quicker and the water will get pushed out wherever it is leaking.
It should have studs not bolts. Bolts will crack the block.
Thanks B, I managed to get some pressure in cooling system, anti freeze is in #3 cylinder, so im hoping head gasket or a head, as long as block is good im a happy person
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It kind of makes sense there was no white smoke from exhaust, as the rad cap is not sealing. so the cooling system wasnt building up pressure. Time to pull the head and hope for only a bad head gasket or head
Did it have bolts in it Steve? If it did or someone had some in prior, it is common for the shank on the bolt head to be longer than the cylinder head is thick. This causes the shank to draw itself into the block if thick washers aren't used and it splits the block. It is repaired by installing "EZ Lock Thread Inserts". Hopefully your good there.
If its not building pressure but still pushing water out, it must be a good size leak. How did the re-torque go? What brand head gasket is it?
B, here's what I found.....First the cooling system as far as I know is not building pressure because the radiator neck is not sealing with the cap, there is a problem with that .
What I found when I took the head off was #3 piston had no carbon buildup like the other 3 cylinders. I cant see any visible crack on the block deck. The head had been resurfaced for flatness ( I hope) and it also looked good. The gasket was copper and that looked good
The only thing I found was the head studs were never tightened down, so far two were even had tight. The studs did appear to have some sort of sealant applied to threads
One if the loose studs was next to # 3 cylinder
Is it possible a loose stud could somehow cause the leak? Id think leaking or not the head gasket would seal it
Im thinking of making a thick rubber head gasket, sealing the cooling chambers and air testing the block.
Any thoughts?-----------------I just saw what I think may be a crack in combustion chamber #3 cylinder ----Going to machine shop asap, I do have a spare head
Last edited by steve welder; 09-26-2024 at 07:41 PM.
Reason: new information
Steve, I believe you have a few things going on there. I would not use a copper gasket unless I was sure both surfaces were milled flat. Copper gaskets should be sprayed with something like Copper Coat. https://www.amazon.com/401612-Copper...8E-&hvexpln=73
I would use a Fel-Pro head gasket. It is much more forgiving of wrong surface finish and flatness. It is just a safer bet in general for the DIY crowd. Copper gaskets require perfection in finish, flatness and torque.
It sounds like you found where it is going if #3 is "steam cleaned". The studs go in finger tight only. Do not put sealer on them. They do not penetrate the water jacket and sealer will make proper finger tight installation more difficult. Clean the threads in the block with a tap, air and brake cleaner. install the studs loosely so they can move around, drop the gasket and head on, then tighten them down finger tight only. When you torque the nuts everything will be just right. Make sure someone didn't put bolts in there and crack the block around the threads.
If the stud nut was loose, yes with a copper gasket it could leak.
The only thing that will work as intended for any length of time is a proper head gasket and install. I would try it again making sure everything is flat and very clean. Torque the stud nuts in proper sequence and in 3 steps. Put the Fel-Pro gasket on dry. https://www.motortrend.com/how-to/im...tortion-check/
Thanks B.... I know the deck was surfaced as was the head.... I went to shop today and machinist confirmed it was a crack, I gave him the head that was on original engine and he will clean and resurface..... The gasket that the shop used when they rebuilt this engine was copper and I ordered another copper one today but given the fact that both head and block were resurfaced if you still think I should not use copper please let me know.....Also I am getting a ground straight edge and will use it to check the block------Again Mr B thanks so much for your expert advise
Steve, I would not use the copper. The modern technology in the newer designed Fel-Pro gasket will definitely help you with a successful seal. Re torque it after a heat cycle and it will last a long time. I do use solid metal copper and steel gaskets in some applications. I have used them in some high pressure engines. Usually when you use solid copper now a days, it is used in conjunction with stainless steel "O" rings and block machining to accept them. This is very effective in blown racing engines and Nitrous Oxide injected engines where cylinder pressure is very high. A plain copper gasket without an "O" ringed block is not as easy to seal or keep sealed as a quality "composite" gasket like the Fel-Pro or, an MLS (Multi Layer Steel) gasket. The modern MLS gasket is used in everything from racing engines to go karts. It is superior for most applications. I think for our "low pressure" 134 Go-Devil", the Fel-Pro composite gasket below is your best bet. Install it dry, very clean, correct side up if marked "this side up", torque it in the proper sequence in three increments and re-torque it after it is warmed up and cooled all the way back down. Make sure those surfaces are flat as you said, and clean. Check that block over with a magnifying glass at those bolt holes especially. If the block was decked by a machine shop, I would hope they looked it over for cracks. If the head was surfaced flat and the block was surfaced flat, I think you were facing how fussy a solid metal gasket can be. The invention if you will, of the "Composite Gasket" of today, was to eliminate the shop call backs on leaking copper gaskets of old.
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