340 Engine Leaking Coolant from Valve Cover Bolt Hole

[Chryco Psycho]

Maybe a bolt was broken in the hole , drilled to get an easy out in there , or to retap the hole or install a helicoil insert & drilled too deep , you could put some JB weld in the bottom of the hole & run a lubricated bolt into the hole to seal below the threads , leave the bolt in there for a bit until the JB Weld hardens so you can at least remove the cover without draining the coolant in the future 

[73_Cuda_4_Me]

https://www.fastenal.com/products/details/1173257

Depending on threaded depth of VC bolt hole, some non-hardening RTV sealant around the above socket set screw should cure it...

[Adams1stCuda]

So been pretty busy the last few days with a ton of other normal life stuff, but finally got around to taking a better look at this issue.  Video shows what I was finding when removing the bolt and two pics show both the depth of this specific hole in the head as well as all four of the others...defiantly much deeper.  Did notice just a touch of antifreeze around one of the valves, but believe that was incidental to me pulling the VC and not internally leaking.  No cracking as far as I could see and no evidence of coolant in the oil.  Still will be changing the oil/filter just in case.  Did notice some discoloration on a couple valve springs.  Don't know if this is normal, but will pull the other VC to compare tomorrow.

Will probably go with the sealed stud option and hopefully plug this leak.  Just deciding if I want to go with studs all around for a uniform look, or just this hole...

https://youtu.be/8f7pz9zG_gY

[Adams1stCuda]

https://www.fastenal.com/products/details/1173257

Depending on threaded depth of VC bolt hole, some non-hardening RTV sealant around the above socket set screw should cure it...

Do like this option, just wonder if I threaded too deep if it would dislodge into the water jacket...

[Chryco Psycho]

You can get different length set screws & see how far down it could go

[Brads70]

Go to your local industrial bolt supplier and get some stainless set screws, they come in various lengths. Liquid teflon then in position.

You can get different length set screws & see how far down it could go

That's what I was trying to say. I think they come up to 2" long ? Nice little allen head to screw them in with and hold if you need to loosen the nut again at a later point ........ stainless ( won't rust)