Replacing Exhaust Manifold Studs

[95Finder]

I am replacing the studs on my 1995 Pathfinder, one of the studs was broken off so I couldn't get vice grips onto it. I drilled into the stud and started threading the bolt extractor into the hole. The bolt extractor snapped off and part of it is stuck in the middle of the stud. What are my options? Can I buy a carbide drill bit that will drill back into the stud? If I bring it to a shop will they be able to somehow get it out. Or do I need to remove the head and bring it to a place that removes fastners using EDM? Any help would be appreciated. Thanks.

Edited May 21, 2006 by 95Finder

[95Finder]

Anyone??? I know other people have done the same thing, it's inevitable when your drilling out studs. Why did this have to be one of the Pathfinders few faults?

Edited May 21, 2006 by 95Finder

[Slick]

i managed to drill into the broken drill bit, then ended up drilling the hole to 5/8th and putting a bolt in there. it works better than the stupid studs, and am highly thinking about drilling my other set of heads to hold bolts instead of studs too....

 

when doin my way of extraction.. please PLEASE be careful of the water jackets.. you can only go down so far before you hit one and then yer fubard.

 

i am not saying my way is right or good.. but it was my last resort.

 

a machine shop would be able to remove it but they would need the head to do so.

 

check out B's write up about removing broken studs

http://www.nissanpathfinders.net/forum/index.php?showtopic=5361

Edited May 21, 2006 by Slick

[Nutz]

I had a similar problem with 2 broken studs(one on each side of course), one of which I broke a drill bit into. After a couple of days and nights on my back, trying every type of extraction tool and drill bit, I had made a mess of it and was getting close to the water jacket. I finally had it towed to the dealer, and after their mechaninics pulled their hair out for a couple of days, their head mechanic told me that they could try to drill them out but wouldn't be responsible if they messed up the head. He suggested that they call in their "laser guru" who they used on jobs like that. This guy is an independent "fixer" who does jobs for dealerships and other shops. They have no idea what he does exactly, (he covers the side of the truck with a tarp and won't let anyone watch) but they said it works. I had no choice so I told them to go ahead, and I'm glad I did. I looked at the heads after he was done and it looked perfect. I was amazed because I had made such a mess of the holes ( they were oversized and out of round by the time I took it in.) The guy must have done some sort of aluminum welding to fill in the holes and drilled and tapped new threads. Probably similar to what a machine shop would do with a head on the bench, but he did in on the truck. It was a perfect job and I didn't have to have the heads removed. If you can find a guy like this, do it. His fee was $300 for both sides, which is a lot less that the dealer tried to charge me for screwing around for several days and still not fixing anything.

 

Hang in there. It can be done, just gotta find the right guy

 

Good luck.

Edited May 21, 2006 by Nutz

[unccpathfinder]

i think carbide would be u're best bet b/c the extractor should be hardened and a drill bit iwll just get hot and dull make sure to use plenty of cutting fluid

[95Finder]

i think carbide would be u're best bet b/c the extractor should be hardened and a drill bit iwll just get hot and dull make sure to use plenty of cutting fluid

Lol, carbide won't drill into it, I am going to grind the bolt down with a tungsten carbide tip(the only thing I found that will cut the extractor) for my dremel until the tip of the extractor is no longer present. Then I will try to drill and extract the bolt again, if this doesn't work then I will probably just end up drilling it out to 5/8 as Slick did and tap it for a bolt, wish me luck.

Edited May 21, 2006 by 95Finder

[95Finder]

Well can't get the damn thing out and I don't have the cash to pull the head and have someone use an EMD machine on it. I guess I will just get a new exhaust gasket and bolt the manifold back on for the time being. When I get the cash I guess I will have to pull the head and take it to a machine shop. Thanks for trying to help.

[Precise1]

What is the diameter of the stud ?? I'll make you a left hand carbide spade drill that will drill out the bolt extractor... PM me your address.

 

Oh, have you tried shattering the bolt extractor ? They are usually brittle, so sometimes you can chip away at them using something pointed and hardened.

 

B

[k9sar]

I've drilled out extractors using a small TC bit and basically burned my way through it. Must be sure there is no oil on it cause you want it to heat up and anneal (sp?) the extractor, making it softer such that you can get through it with the TC bit. Then use a normal drill, at low speed, to cut a new hole. Option then is to try to get the exact size and centering so you can pick out the stud threads from the head (not likely) or retap the thing.