coolant leaking from head stud nut

lincolnlocker · Jul 28, 2014

that is correct. I have coolant leaking out of the top of a head stud nut. its the driver side rear outside corner to be exact. oil is clean, no coolant in it. just running out and down. what could cause this and any way to stop it for now?

isootmypants · Jul 28, 2014

Sounds to me like the stud itself is cracked.

webb06 · Jul 28, 2014

lincolnlocker said:
that is correct. I have coolant leaking out of the top of a head stud nut. its the driver side rear outside corner to be exact. oil is clean, no coolant in it. just running out and down. what could cause this and any way to stop it for now?

On my 6.4 when this happened the block was cracked. You could try removing the stud and putting on some pipe dope to temporarily fix it.

Since its an exterior stud I don't think you'll have any trouble with coolant and oil mixing

lincolnlocker · Jul 28, 2014

isootmypants said:
Sounds to me like the stud itself is cracked.

how could that be? it was tq'd to spec and then hot retq'd by mike himself.. wouldnt think they would crack. but there still shouldn't be coolant coming out of there unless head or block is cracked or gasket is jacked right? I dont know weather or not the stud goes through a coolant passage due to not knowing what the internals look like or how coolant flows through any of it. I have never had to mess with that aspect of a 7.3...

webb06 said:
On my 6.4 when this happened the block was cracked. You could try removing the stud and putting on some pipe dope to temporarily fix it.

Since its an exterior stud I don't think you'll have any trouble with coolant and oil mixing

what part should the dope go on? just the top where the nut is or threads on the block side too? I would think that it could potentially hurt whatever is cracked worse.. but again, I have never had to deal with this issue.

webb06 · Jul 28, 2014

lincolnlocker said:
how could that be? it was tq'd to spec and then hot retq'd by mike himself.. wouldnt think they would crack. but there still shouldn't be coolant coming out of there unless head or block is cracked or gasket is jacked right? I dont know weather or not the stud goes through a coolant passage due to not knowing what the internals look like or how coolant flows through any of it. I have never had to mess with that aspect of a 7.3...

what part should the dope go on? just the top where the nut is or threads on the block side too? I would think that it could potentially hurt whatever is cracked worse.. but again, I have never had to deal with this issue.

The portion of the stud that threads in to the block. Don't put any around the nut. That will mess with the proper torque.

Pretty certain the studs don't go through the coolant passages

lincolnlocker · Jul 28, 2014

webb06 said:
The portion of the stud that threads in to the block. Don't put any around the nut. That will mess with the proper torque.

Pretty certain the studs don't go through the coolant passages

so that would help if the block was cracked. but what if head is cracked? and it leaks out very easily. I have a pressure gauge plumbed in to the coolant system and it barely registers any pressure and its leaking out of the nut....

webb06 · Jul 28, 2014

That will only help if the block is cracked.

lincolnlocker · Jul 28, 2014

isootmypants · Jul 28, 2014

I thought it did go through a passage. I could be wrong. I don't have a motor apart to look at right now.

lincolnlocker · Jul 28, 2014

would it be a stupid idea to take the nut off and put some permatex around the stud(not on the threads) and then re tq the stud? or be better to just let it leak untill I can get around to pulling the motor?

isootmypants · Jul 28, 2014

lincolnlocker said:
would it be a stupid idea to take the nut off and put some permatex around the stud(not on the threads) and then re tq the stud? or be better to just let it leak untill I can get around to pulling the motor?

Honestly I would just clean off the area, leave it torqued and just smear over it for now

golfer · Jul 28, 2014

none of the 7.3L studs go through coolant passages...

around them, yes...but no (7.3L) studs are exposed to coolant (unless the block is cracked).

isootmypants · Jul 28, 2014

golfer said:
none of the 7.3L studs go through coolant passages...

around them, yes...but no (7.3L) studs are exposed to coolant (unless the block is cracked).

Well Dave said it

lincolnlocker · Jul 28, 2014

golfer said:
none of the 7.3L studs go through coolant passages...

around them, yes...but no (7.3L) studs are exposed to coolant (unless the block is cracked).

Thank you for the clarification sir!! guess im gonna be on the hunt for a block

isootmypants said:
Well Dave said it

yeppers.

well ***.....

thanks fellas.

TyCorr · Jul 28, 2014

lincolnlocker said:
Thank you for the clarification sir!! guess im gonna be on the hunt for a block

yeppers.

well ***.....

thanks fellas.

That blows man! 7k out of a rebuild. About $1100 per 1k miles.

Are you just going to get a forged motor and swap things over? Get back to it?

After this experience, unless you can afford one from swamps or nltd, id use a stock fr motor.

lincolnlocker · Jul 28, 2014

TyCorr said:
That blows man! 7k out of a rebuild. About $1100 per 1k miles.

Are you just going to get a forged motor and swap things over? Get back to it?

After this experience, unless you can afford one from swamps or nltd, id use a stock fr motor.

prolly. but no time soon. this one is balanced but 30 over so I dont know what im gonna do yet..

DEEZUZ · Jul 28, 2014

,,,,fawk....

lincolnlocker · Jul 28, 2014

CTC DEEZUL said:
,,,,fawk....

yup..

I figured it was cracked but was hoping for a different possibility.

DEEZUZ · Jul 28, 2014

that sucks man. I know you work your truck too. All the more reason for me to remain stock in the most important aspects.

DocBar · Jul 28, 2014

This might have nothing to do with Lincoln's issues, but I'm a big believer in sleeving the cylinders. There are cracks that magna-fluxing can't find. Cheap insurance, imho. Going .xxx over in a diesel just isn't the same as in a gasser. I'd rather stay closer to stock compression. Just my .02 worth.