Exhaust manifold stuld broke: anyone have good luck replacing?

[MarkRobinson]

I can't believe I didn't replace all 8 of the exhaust manifold studs when I did my head R&R last February: I had them on my shelf!

:/ Hoping I don't need to use an extractor...

[Techno Duck]

Depends which one really. I bought my 951 with a broken one. Had all sorts of ideas using a reverse drill bit on a right hand drill and a few ideas to make a jig to keep the bit centered. Ended up pulling the head to do the headgasket rather than bother trying it.

Here was one idea for a jig..

[MarkRobinson]

Yeah that's my worry: I suppose I'll see how far I can get before I opt. to remove the head. :/

[Pete R]

So.... 2011 is going pretty good. I'm assuming it broke flush or you wouldn't be asking. If you know anyone that is a good enough TIG welder (and they can get 2 hands in there) they should be able to build up enough of a nub on the bolt to remove it with vise grips. The welding heat usually make it loose too. I have removed several 928 bolts this way.

[Pops944]

On the line of welding build up of stud - if you can get a build up started on the stud, build up until you can fit a nut over the build up, then weld the top of the nut to the build up. As Pete R said the heat will help loosen it, and with the nut on it you can use a socket or wrench to turn it out.

[Pete R]

nice , I like the nut idea, good for the real stuck ones, I hope I never have to try it, I've always been fortunate enough that the vise grippers were strong enough. good tip

[kdjones2000]

Mark, did it break while trying to remove it, or just during normal driving.

I had one snap on my car, and my mechanic replaced it fairly easily (not sure of the details). From what I have heard from others, if it just snapped on you, you may be able to almost unscrew the remaining part by hand if you are lucky.

Keith

[Pettybird]

I have one broken from normal use and I'm using it as an excuse to do a top end check/rebuild.

I had to pull a head on one of my Superbirds to get a broken exhaust stud out, too--that didn't make me happy.

[MarkRobinson]

When I got it back from the body ship it had already popped: now hisses quite a bit: can't get it inspected (of course). Have'nt tried removing it yet: will do so after my 911 engine swap is complete.

[Lawrence Coppari]

Here's what I did back in 2000 without removing the head. It's an old post of mine on the 944 side of this site. Originally I purchased a Snap On tool for removing broken bolts. I drilled out the center of the stud then inserted the tool. However the tool slipped and the stud did not come out. It was the one closest to the firewall so it was a real PITA.

"I eventually got it out by purchasing a diamond bit and a tungsten carbide bit for my Dremel and slowly ground the thing away until it was so thin that I could bend it radially. The diamond bit was used to cut radially to sever what was left of the stud. Be careful (if you do this) and not remove much metal from the head. Fortunately, one is ferrous, the other is not so you can use a small magnet to feel where the steel is and where to remove it. The magnet also removes the steel metal particles. That was last summer. It has worked properly ever since. Oh, after you get the stud out, chase the threads with a tap. I lost two threads for about 45 degrees. But 9 grab so I'm ok."

Now it's 2011. No problem with the new stud.

[toyhole]

Hello. I'm new to the 951 game, and I'm replacing all of my exhaust studs on my 951 since I had one break. I've heard that the exhaust on the these are prone to cracks. So I'm asking the experts here how tight/torque do you apply when installing the exhaust studs? I really couldn't find any for sure specs on them.

Thanks,
Bill

[Pettybird]

bottom them out and gently nudge them past that. They snap from the heat, not improper torque. Make sure the nuts are right, though.

[Lawrence Coppari]

The one that I had break off was due to the other one on the same flange loosening placing the load and allowing any resulting vibrational forces to be on the one that was still tight.