The Stovebolt Site Forums The Shop Area Engine Shop Pinhole leak in head

This is my first post, mostly because I've been able to get my questions answered up to this point by searching old posts. I just got my 54 3100 with original 235 back from a complete engine rebuild and noticed it was leaking coolant below the plug on the 3rd cylinder. The shop tells me it has a small pinhole leak in the head which was not discovered when it was magnifluxed. There is no issue without the way it runs (perfect) but I obviously don't want to live with it.
Could I just clean it and use JB weld to seal it ?
Thanks,
Richard

Welcome

What does the shop recommend? If the shop was the one that magnafluxed the head and did the rebuild, I would think that they would be the one to repair it. There is a way to STITCH WELD a small crack, but I have never done that.

You can also find another clean head and have the shop rebuild it using the old parts.

I am sure there are other ideas and others may follow.

Drain the block and try JB, nothing to loose.

Thanks for the feedback I'm going to try Blue Devil gasket and head sealer and then the JB Weld and hope for the best. I can always start over and get another head..

With out seeing where it is at, I have repaired pinhole leaks in engine blocks by drilling, threading and installing a allen head set screw. Keeping it as small as possible to obtain threads. Seal the set screw.

just have to wonder what else they missed in their magnaflux? I'm not so sure I would want that shop to do any more work for me. I'm not certain of the condition of your head, but often pinhole leaks come from severe rusting on the OTHER side of whatever has the pinhole leak. (I used to work on ships, I have seen a lot of rust, not real romantic I know, but hey....)fortunately these heads aren't really hard to come by.

There also are additives that go in the coolant to seal small water leaks. I used something like this years back on a GMC that leaked and it worked good as a temporary fix. Sorry don't remember the name of this product, check with local auto parts stores.

Mine is in the machine shop right now. I'm having mine welded up, new guides and a three angle valve guide/replacing the springs too.

Welcome,rknuttall! Years back,a girl brought her car into the shop,(in the dead of Winter),complaining that her engine was leaking antifreeze. Come to find out,she was too cheap to buy anti-freeze,and the block had a 5-inch-long crack,about 1/16-inch,at the widest point. I took a rat-tail file,and cleaned the crack good,(Now they have "Dremels":))and then went over the area with a magnet,to lift as much of the shavings that I could,out of the damaged area. I applied a bead of "J.B Weld" to the crack,and kneaded it into the length of the crack,and then applied a second bead on top of the first one and kneaded them both together. I then applied a "trouble" light,(with a 60-watt bulb),(Heat Source),as close to the repair as I could,to help the bond cure, over-night. She drove the car another three years,until the tranny "crapped". The engine didn't leak a drop after the "J.B." fix. I'd give that a try,first. I've also had great results with the "Allen-screw fix",just a little more work,but not too complicated. Good-luck!

Thanks everyone for all the great input, I used the "Blue Devil Head Gasket Repair" and it seems to have worked. I will add the JB Weld as well. The set screw fix will be the next solution if it starts to leak again.