Exhaust Manifold Stud Extraction

When I got the exhaust manifold replaced in my 1st. gen. Eclipse, one of the studs snapped off inside the head. Nothing to Vise-Grip on to. I asked the mechanic to skip extracting this stud to save me some labor money on what was already becoming a very expensive trip. He used an OEM metal 4-layer gasket to help compensate for the uneven torquing. Now I get to deal with the stud on my own. Joy!

Here it is when it was still intact ,along with the original manifold that was cracked in 6 different places. It's the uppermost left stud in this picture (roughly under the "D" in "DOHC), I'll try to get a better pic tomorrow.

Tips on getting the old one out? Preferably without having to remove the exhaust manifold? Before anyone says "Shotgun!" note that I am already considering taking one to this car...

Slide some sort of steel tube in there to protect the threads and weld it to the remains of the stud?

Shotgun?

You'll have to drill the stud with a reverse drill bit and see if it will come out. Otherwise, drill the stud with progressively larger bits (cutting fluid and a drill press are recommended here) until you can cut new threads in the remnants.

For an on the car repair, use the manifold as a guide and go slowly and realize that the aluminum is softer than the steel, so don't miss!

I would have had them do the stud, it would have been cheaper as the labor isn't that bad and they'll get it in straight.

If you have the engine out and have lots of extra time and money, you can try EDM (electrical discharge machine):

http://www.pelicanparts.com/techarticles/101_Projects_Porsche_911/95-Tapx/95-Tapx.htm

turboswede wrote: I would have had them do the stud, it would have been cheaper as the labor isn't that bad and they'll get it in straight.

+1. There are few things I will pay someone else to do, but jobs like that are on the list.

On a side note, isn't it amazing how expensive "cheap" unusual winter beaters can get? Now I know why all my friends buy clapped out auto Corollas for winter.

Did it snap in the course of trying to remove the nut? Or was it broken due to the thermal expansion / contraction cycles?

On the L28 in my Datsun, the two studs on either end tend to get broken due to thermal expansion. The stud itself is easy to remove with an ez-out or welding a nut on it.

In either case, I wouldn't try drilling it until I tried the welder first. The heat the welder applies is often a big help.

In reply to SlickDizzy: Tell me about it. My "build thread" is more like an ongoing bitch session about all the crap I've had to replace on this car.

After reading all these replies, I am regretting not having the shop do the extraction for me.

In reply to mikeatrpi: It broke during nut removal.

if it broke during removal then the threads are probably seized. don't try an easy out, it will likely snap off. your best bet is welding a larger nut on the stud

is it causing any problems?

if not, shut the hood and walk away from it... find something useful to worry about..

if it's leaking, then goop the area with some high temp silicone, shut the hood, and find something useful to worry about..

Answer depends on if it snapped off with a little stub, flush, or below flush.
Stub or flush, as said, you can try welding on a nut.
Hold the nut in place, and pop a quick bead right into the center.
Even if the weld breaks when you try it, not really any worse off.

If below flush, have a friend with a lathe drill a hole in the center of a short bolt with same thread. Make the hole as big as you can without getting too close to the threads. Screw the drilled bolt into the hole, and then use the hole as a guide to drill a centered hole into the stuck piece.
At this point, you can maybe try a slightly larger drill to remove all of the broken piece except the threads, and then pick the threads out with an awl and needle nose, or maybe even a tap.
Or just bite the bullet and drill the whole thing out for a thread repair insert.

Good luck.

Aluminum block? Drill the whole thing out with a bit just slightly larger than the bolt - this will also remove the threads in the block. insert a replacement steel stud into the now threadless hole. Braze some HTS-2000 Aluminum repair rod stuff into the hole, around the bolt. It should create its own threads, and be stronger than the block when its done.

LINK TO THREAD REPAIR

YMMV, but a buddy did this with a trans bolt ear that broke off...clamped a bolt between 2 pieces of sheet metal, and just gooped the braze rod in there with a plumbing torch, created a whole new ear - threads and all. I think theres a youtube vid out there showing this, which is where he got the idea.

I would try welding a nut to the stud. This has been my go to way to hadel things like this. The key is to clean the point where the stud and nut are welded as best you can so you get good weld penitration to the stud. Add the heat from the welding process and they usually come rite out.