Got what appears to be a small anti freeze leak around one of the manifold studs. Do the holes extend into the block water jacket. If they do what do how do you seal it?
Chevy V8s have studs which go into the coolant jacket. There is a thread sealant available to do the job, but I am not familiar with it. A generic thread sealant may be good enough.
Hope this helps.
Allan from down under.
The holes do not extend into the water jacket, however a crack can occur there or if someone drilled out to re tap the threads it can go into the water jacket. Or less likely the inside of the block can rust out at that point.
Good luck fixing it.
I've had a mysterious, small, green seepage around my engine for years. -I pretend it's not there and so far, the engine does the same. -My coolant level doesn't decrease noticeably, so—eh.
Clean it squeaky clean and use some Ultra Black and you'll not have any more leaking.
It also could be from one of the Freeze plugs.
I too has the exact same issue on two of the four studs and was relieved to find it wasn’t the head gasket of my nearly rebuilt 1910 motor!
In my usual way I did a overkill buy increasing the length of the threaded section of each stud by a 1/2” and added another nut, flat washer and O Ring. Using Locktite 567 on the stud threads as usual when screwing them back into the block to the correct position then tightened the secondary nut just enough to load up the o ring slightly on the side of the block.
Most likely the Locktite fixed the leak but who cares, it doesn’t leak anymore and the extra nut etc is well hidden behind the manifolds. It’s only has to hold the weight of the water and I’m confident that the four holes were dead ended from new but after years of use and possibly over tightening of manifold studs, loose threads etc cracks must have developed into the water jacket.