Fired my new BB this weekend and we noticed water seeping from a head stud, #2 cylinder. To remove the stud and silicone it would require removing the header etc. which I'd really like to avoid. I'm running distilled water and water wetter right now. Can I use a stop leak product to cure this problem? If so, are some better than others? My motor builder is out of town this week otherwise I'd ask him. We ran the engine very little as we are still tuning etc. however when I changed the oil there was not H20 in the oil so I'm pretty sure it is just a stud issue.
Suggestions and comments appreciated.

I've had good luck using RTV on the studs during assembly. If you want to avoid all the hassle like you described I would try a "horse pill" from the GM parts counter. You might try to do a search on it and check out some previous results from others folks using it. Seems to work pretty well.

supposed to use thread sealer on head bolts,surely can't be that much trouble to do it right? :confused:

Is this the only stud seeping water? How can you be sure. If you have run it very little it will likely get progressively worse. Do it right, it is worth it, otherwise it will always be in the back of your mind. Pull the header and then check EVERY stud to make sure.

I had that problem once and the GM "horse pills" plus another brand name leak stop didn't help. I had to remove the header bolts, drain coolant down to below the bottom of the bolt (through the block plug), remove the head bolt, clean and dry the threads of the block and bolt (I used rubbing alcohol), and put Permatex #2 on the bolt threads.

stud In a word, there's your problem.

Do you really need those? or are they some sort of "all the big time guys do it so I must need to too" kind of thing?

Every single motor I have ever built myself or seen someone else build with studs, they leaked. Every single one. Some more than others, a few only slightly, but every single one just the same. Usually from first start-up on, sometimes just from filling up before the motor even cranked.

Now granted, past performance is no guarantee of future results, as the stockbrokers like to put in the finest possible print in their ads; but those odds don't really appeal too strongly to me.

If you don't really need them, lose the studs, and put a good quality set of bolts on there, like ARPs or something; and use Loctite PST (pipe sealer with Teflon) on the threads, and under the washers, and between the bolt heads and the washers.

Put some Bars Stop leak in an your problems solved.

I have to agree that head studs are definitely not needed for your deal.
Bolts are a lot easier to deal with in most applications.
But,,, since you already have them,,

In applications where we use studs that go into water I locktite them in almost all instances.
When you locktite them you must install the studs, install the heads & torque them lightly & let the locktite set up or torque completely if you are done checking things.

I for one am not a big fan of ARP's sealant.
I've had too many leakers especially with studs.
Works excellent on pipe threads though & fair on bolts.

The ARP is good stuff, just don't use it with head studs. It will likely leak.
With studs you are not turning the male /female threads against each other like you do with a bolt & the Teflon stuff regardless who makes it works best in an application where you are actually tightening or "setting" the threads against each other like pipe threads do.


For years all I ever used was Permatex Hi Tack or non hardening sealant #2 & then started using Hylomar & never had a leak.

Permatex has a somewhat new thread sealing compound we are using now that works great.
I like it better than any of the other stuff we have used.
Oddly enough it is called Thread sealant

I use the HI Temp (59235) as Permatex tech says it is the same as the hi performance only with a higher temp rating.

Also, I have had some luck sealing after the fact with the "pills" sold by Silver Seal called Rebuilder Tabs I believe. They are designed to seal up minor leaks at core plugs & threads.
Probably the same stuff sold by GM mentioned above.

Since you already have it together, buy a pint of Moroso Ceramic Engine Seal (pn 35500, about $12) and follow the instructions... it works.

In the future, Locktite the studs.

Either the Moroso sealer as 383Malibu said or use a can of K & W Block Sealer which is available at most auto parts stores. Stuff works great, use it once and your done ... untill you pull and reinstall the studs.

Like Wolfplace, I`ve always used Permatex #2.
No leaks with studs so far with it.
Went to get some the other day,couldn`t find it instead they had a #9 called "Tack & Seal" gasket sealant.
It had all the properties of the #2, as listed on the package back, but with "gasket positioning" added where #2 didn`t.
I hope it works.

Never used Hylomar on studs before, Wolfplace, which is more effective in your opinion, the Hylomar or #2?

Originally posted by BigRed-L72:
Like Wolfplace, I`ve always used Permatex #2.
No leaks with studs so far with it.
Went to get some the other day,couldn`t find it instead they had a #9 called "Tack & Seal" gasket sealant.
It had all the properties of the #2, as listed on the package back, but with "gasket positioning" added where #2 didn`t.
I hope it works.

Never used Hylomar on studs before, Wolfplace, which is more effective in your opinion, the Hylomar or #2? =
I think the Hylomar is probably a little better but it's hard to argue with something that has been working for years :D
I haven't tried the new Permatex Thread Sealant on studs yet but according to them it's real good stuff.
Every time you look there is something new :(
I personally like to loctite them.

"Here's a blurb from Valco about Hylomar:
GASKET MAKER AND THREAD SEALANT
HylomarŽ is a polyester polyol-based compound that turns from a gel into flexible putty within minutes of application. Originally developed by Rolls Royce, where it performed under the most stringent aerospace tolerances, Hylomar brings superior qualities to automotive applications. Its non-hardening formula maintains seal integrity even when subjected to thermal distortion and vibration.

Hylomar is impervious to oil, gasoline, glycol and other engine fluids. Hylomar is oxygen-sensor safe, seals gaps .01" or less, and performs at constant temperatures up to 600°F. with Hylomar, components are assembled, reused and reassembled with ease. "