I broke the head off a bolt on the intake manifold today. I really don't want to half to try and deal with extracting the bolt, and extracting broken bolts is something I've never really been that great at. Rather than risk messing things up even more, do you think I could get away with leaving this or do you think I'll end up with and intake manifold leak? It's post supercharger so this would be pressurized air.

 

That really sucks, but I think you have to extract it and replace it.

If you remove the manifold/supercharger you may be lucky enough to have sufficient of the bolt showing whereby you can unscrew it.

Carefully "unscrewing" it with a small, sharp metal-chisel sometimes works.

Then there's drilling and using an extractor bit.

If you don't feel confident enough enlist the help of someone experienced, but sorry, I think it has to come out.

 

I took off the intake manifold (technically I guess it's called the charged air cooler) and there was just enough of the bolt sticking up that I could grab it with need nose vice grips and twist it out.
Now I'm wondering if I need to replace the gasket? It was a brand new gasket but some of it stuck to the intake manifold.

 

A lot of the time, once its snapped and the tension is off, the remaining threaded bit unscrews quite easily. I had to do a cylinder head bolt on this engine as the hex rounded off, but once the hex head was drilled off, the shank literally unscrewed with my fingers. Yours is not a bolt that is typically welded in place with corrosion so I think it will be similar. It looks easily accessible as-is so I'd give the screw extractor a try assuming there's not enough protruding to get hold of with vice grips or similar. Just thinking about how I'd do it, I'd order a long-ish (so the drill chuck clears the manifold runner), high quality cobalt bit for drilling metal, whichever size goes with the chosen extractor. Then I have a Smithy 3-in-1 lathe, so I'd measure the bolt hole in the intake and make myself a centering guide for that drill bit so that I could drill the broken bolt dead-center. Without a centering guide, you might could get what they call a pocket-hole drill bit with the large flute diameter matching the bolt hole and the small pilot point approximately the size for the extractor. Then once drilled, the short extractor could be inserted, but the intake runner may be too close for the chuck so you might have to remove the intake manifold to be able to manipulate the extractor. Keys tho are having a high-quality, cobalt bit for drilling metal and getting it centered. You don't really need reverse drill bits, theoretically that's to keep from screwing the broken bolt in even further while drilling, but its really not critical in this application as its probably already near bottomed out.

 

Congratulations on being able to extract the remainder of the bolt!

As for the gasket, because parts of it have stuck to the manifold surface, you should scrape those off and fit a completely new gasket.

 

Damn, that means waiting another week for the gasket to arrive!

 

If you have not removed the bits of the gasket stuck to the manifold, you could just apply a thin coat of sealant to the gasket and assemble. The pressures under boost are very low and it is only the temperature to take into account so a good sealant for temperatures up to some 150C will do.

 

Try his answer: nothing to lose. If it leaks, plan B. But start using 1/4 inch drive sockets.

 

Already ordered new gaskets. Just going to redo so I don't have to do it again later.

 

MS's and JH's suggestions are perfectly safe and good solutions, and would probably work as well as a new gasket, but a new gasket will definitely be the right solution, so a wait of a week is worth it, and you will be sure it is done right.

 

It's just annoying because it means working backwards yet again, I'm getting pretty tired of that. So much of getting this car back together seems to have involved undoing and redoing something I've already done. I've had some weekends I worked on it all day only to be no further along or even further behind. Its a wonder I'm making any progress on this car at all.

 

Welcome to my classic car restoration hobby. I'll assemble a bunch of stuff and then later while going through the boxes I'll discover a ziplock bag containing a tiny little part that should have been installed before that other stuff. When you took it apart five years ago, its hard to remember everything and in what order it goes back together. Heck, it'd probably be hard to remember if I took it apart last week or last month, but I'm never that fast.