DallasClement

I was a num nut and accidentally broke off a piece of the block when trying to remove the timing chain cover. The bolt was hiding about midway up the cover on the firewall side. I should have been more patient as I was trying to jostle it free. It snapped like a twig. Am I toast or do you think this can be fixed? I am worried that without the pressure of that bolt holding things together in that corner that there will be a big oil leak. The whole purpose for doing this was to fix some seepage from the gasket that had worn down over time.

Colin42

You could try jb welding it back on. Put the timing cover back on and run all the bolts in to make sure it stays in place

BrotatoChip

If there's still enough surface for RTV/Hondabond I would definitely try without the bolt. Much better option than replacing the block...

DallasClement

Thanks for the ideas. Would you recommend just cutting off the bolt so that there is not an exposed hole? Also, do you think it would be worth trying to drill a new hole to the side of the broken area to place a new bolt?

BrotatoChip

Do you have pictures of the block side?

DallasClement

Here's a few more pics of the block side. This little ear piece on the block that broke off is pretty small. I'm wondering if I can get away with just a JB weld of the broken piece back onto the block as @Colin42 suggested. It's such a small piece, I don't think it will be possible to fasten it with a new bolt into the block. As you can see in the pics, the mating surface in the break area is very thin. So I think I will need the additional surface area of the broken piece. The real question is without any bolt holding it in place, will it leak there with just the gasket holding it together?

BrotatoChip

That's pretty ugly. See the pics below. When you go to reinstall you run a bead of RTV/Hondabond on the flat surface along the red line. You can see a good chunk of that flat surface is missing. I was hoping there was enough of that surface left to still get a good bead, looks like there's maybe 1 mm left. Might work, might also leak.

I think that bolt and chunk of block need to come off no matter what. You can try using JB weld to stick it back on. If you do this, you would have to ensure that flat surface is still flat. May require some sanding. If you do that, I also would leave that bolt out to avoid it breaking. Without that bolt I don't think the RTV/Hondabond would have any issues sealing (as long as the piece is JB welded really well). Weather you try to stick the piece back on or not, definitely make sure the RTV/Hondabond is way on the inside where the remaining surface is.

DallasClement

Thanks. This helps tons. I also feel this is the best approach. I'll clean everything up real good and give it a shot. Wish me luck! I'll let you know how it goes.