broken exhaust manifold stud

take the manifolf off, then try to grip it, with vise grips or something similar, let some penetrating oil soak on it for a while. BTW, why did you ask about taking the manifold off? what were you doing taking bolts out if that wasn't what you were doing?

Remove the manifold and take a nut the same inside diameter as the broken stud, place it over the stud, centered as close as possible. Then fill the hole with weld. The weld will stick to the broken stud. Once it cools, unscrew the stud using the welded nut as a grip. Works everytime. The extreme heat will free the threads when you weld the nut over the stud.

They sell several types of stud removers, Welding a nut on and vice grips are good ideas too. I would not recomend easy outs thoguh. They put an outward pressure which makes bolts fit tighter into holes and can seriously screw over threads. The welded nut works best as it heats up the bolt and lossens the rust. But as your heating up the bolt it is actually expanding, becoming bigger inside the hole which can make it harder to remove while hot. If you can after welding the nut drill a hole down the center of the stud as far as you can. Then heat up the stud again and try turning. This makes the metal expand inward instead of putting pressure on the out side walls. Also a few whacks with a hammer on the stud and around it on the head will help loosen it also. I would suggest a brass hammer for hammering around the head though as you dont want to damage it.

D.Hearne said:

Remove the manifold and take a nut the same inside diameter as the broken stud, place it over the stud, centered as close as possible. Then fill the hole with weld. The weld will stick to the broken stud. Once it cools, unscrew the stud using the welded nut as a grip. Works everytime. The extreme heat will free the threads when you weld the nut over the stud.

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I've used the exact same method many times and it has yet to fail me. Only problem is if you don't have or acess to a welder. If that is the case hopefully you can take it somewhere and pay someone to weld it. Mustangchris gave some good insight on a couple of methods as well. Good luck!

Here's a couple of general broken bolt removal tips I've picked up from some of the more experienced machinists in our shop. Left-handed drills are your best friend most of the time. They usually drill most of the way through, but as they reach the end, they grab the broken bolt and unscrew it. If you do decide to use heat, be aware of what you're heating. Heating a steel bolt in a cast iron heat causes the bolt to expand (cast iron doesn't grow much, which is why they make blocks from it) more than the head, thus locking it in place. The exception is when you do what Hearne says, heat the bolt to break the rust bond, then let it cool completely. This also causes the bolt to shrink slightly when it's cool. If a bolt is broken off below the surface and you have access to an arc welder, there is a rod made that welds to the bolt, but not the threads, therefore it "builds" a bolt. Once you get it built up to the surface, you simply weld a nut on it, hope for the best and unscrew it. If all of the above fail, find a shop with an EDM machine. They make portable ones that will come to your site, and it's not cheap, but sometimes you have no choice. Especially if you tried using an EZ-out and broke that off in the block! Once you do get the bolt out, make sure to prevent the next broken bolt by using an anti-sieze compound.

mustangchris said:

They sell several types of stud removers, Welding a nut on and vice grips are good ideas too. I would not recomend easy outs thoguh. They put an outward pressure which makes bolts fit tighter into holes and can seriously screw over threads. The welded nut works best as it heats up the bolt and lossens the rust. But as your heating up the bolt it is actually expanding, becoming bigger inside the hole which can make it harder to remove while hot. If you can after welding the nut drill a hole down the center of the stud as far as you can. Then heat up the stud again and try turning. This makes the metal expand inward instead of putting pressure on the out side walls. Also a few whacks with a hammer on the stud and around it on the head will help loosen it also. I would suggest a brass hammer for hammering around the head though as you dont want to damage it.

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There's no need to drill a hole thru the stud, once you weld a nut on over it, it will come out everytime. Just let it cool a minute or so.