Stud extraction help needed

My buddy and I are failing to extract an exhaust manifold stud that is broken just inside the head. It's a '90 Saab 900, so the engine is laid over 45*, making it hard to see/drill. Still, we've drilled a hole in pretty straight, but a bit has broken off so can't drill any more or get an ez-out in. So, um, yeah, we're not having a whole lot of fun at the moment.

Are we berkeleyed? I have no ideas at this point short of pulling the head off. Any suggestions greatly appreciated...

Taking the head off will be the easiest way to avoid headaches. A little extra time with a wrench is much better than two handfuls of bloody knuckles.

You need someone who is real good with a welder. I've removed lots by building up the end of the stud, then welding a nut on. It takes patience and a light touch, but coming out of aluminum is usually fairly easy. Cast iron, a bit tougher. Steel, hard.

Ow. We were doing good till the drill bit broke off. Here's something I have seen done a few times. Most recently I saw a busted off glow plug removed from a Mercedes engine this way:

Get a bolt the same diameter as the busted one. Grind off the threads. Use a MIG to build up a weld blob on top of the busted bolt. Clean the weld smoke off of the blob. Stick your modified bolt on top of the broken stud and hit it with the welder. Try to remove the bolt. The weld will probably break, so be ready to try this a few (or more) times. Eventually the busted bolt will start to move, I think it's in no small part due to the welding heat.

EDIT: Streetwiseguy beat me to it.

Question...

While removing the head is indeed no fun, are the alternatives worth it?

This is EASY machine shop stuff. Is re-torquing the head really that tough?

Thanks for the advice. So, uh, yes, I think we're berkeleyed. We neither weld nor know someone with the skills. My friend doesn't know how to do the head job, so I guess that'd be me.

Sometimes, being a shadetree with tools and willing to help friends takes up a lot of time: this work started with a few hours that turned into the whole day, and will now require a couple more, realistically. It's coming on the heels of a clutch r&r on a friend's Peugeot Mi-16 (PITA) and an engine removal from another Saab (easy but snafu-filled).

GRM Obvious Lesson of the Month: Do not use Harbor Freight extractors and drill bits when their failure could mean r&r'ing a cylinder head.

Don't use Harbor Freight ANYTHING unless failure is an acceptable outcome.

Bryce

Nashco wrote: Don't use Harbor Freight ANYTHING unless failure is an acceptable outcome. Bryce

I am going to tattoo that on my forehead, backwards, so I am reminded of that truism every time I look in the mirror.

That said, they were my friend's bits/extractors. I shouldn't have let him use them...

Late advice, sorry, but maybe next time for someone...left handed drill bits sometimes just walk the stud out.

Nashco wrote: Don't use Harbor Freight ANYTHING unless failure is an acceptable outcome. Bryce

+eleventybillion.

Consider this an oppurtunity to upgrade your studs. Retap the head a size or two larger. Example: It's got 8mm studs, now, step up to 10mm.

The bonus? Added strength for your manifold to rest on.

Ranger50 wrote:

Nashco wrote: Don't use Harbor Freight ANYTHING unless failure is an acceptable outcome. Bryce

+eleventybillion.

nothing wrong with HF products... as long as you keep in mind what you have and what you're trying to do.... don't try to make a Pittsburgh do the same job as a Snap On....

So how many exhaust manifold studs does your friend really need?

+1 for the welder. I've done it a few times and I'm about to do it tomorrow.

~Alex

blizazer wrote: So how many exhaust manifold studs does your friend really need?

That's a thought. If it has 10 will it make 50k miles on 9?

Aluminum head + iron exhaust manifold...doesn't JB Weld make a product for that???

petegossett wrote: Aluminum head + iron exhaust manifold...doesn't JB Weld make a product for that???

Yep.

Xceler8x wrote:

blizazer wrote: So how many exhaust manifold studs does your friend really need?

That's a thought. If it has 10 will it make 50k miles on 9?

There are seven studs. The engine is turbocharged, and boosts well beyond stock levels, so I'm skeptical that a new gasket would last long with a stud missing. That said, I will offer him the option, with the caveat that I will not help him with another, future replacement.

Worst part about a broken exhaust mani stud if it sucks in oxygen (which most will do) it'll make the o2 sensor run leaner and the ecu will add fuel. So the sensor will see a normal amount of oxygen/exhaust but really it'll be dumping fuel.

~Alex

Nevermind.

Nashco wrote: Don't use Harbor Freight ANYTHING unless failure is an acceptable outcome. Bryce

[giggle] I was just there yesterday, picking up a drill. I bought the extended warranty. I figure why not, I'll definitely kill it, I may as well get another one [or three or four] for free.

93celicaGT2 wrote: Consider this an oppurtunity to upgrade your studs. Retap the head a size or two larger. Example: It's got 8mm studs, now, step up to 10mm. The bonus? Added strength for your manifold to rest on.

ha! who would be so stupid as to hang a cast iron manfold AND turbo off of 6 8mm studs? oh, right, fazda...

even better when you're being careful and the threads come out with the studs

Strizzo wrote:

93celicaGT2 wrote: Consider this an oppurtunity to upgrade your studs. Retap the head a size or two larger. Example: It's got 8mm studs, now, step up to 10mm. The bonus? Added strength for your manifold to rest on.

ha! who would be so stupid as to hang a cast iron manfold AND turbo off of 6 8mm studs? oh, right, fazda... even better when you're being careful and the threads come out with the studs

Heh, to their credit, i think i have eight studs. But yes. I haven't bothered doing mine out to 10mm yet, because i haven't had any problems yet, though out of my studs seems to have become one with the nut, but at least it didn't pull the threads out.

When the built head goes on, i'll go to 10mm since that will hopefully be the last time the manifold comes off.

It sounds like you have a bolt torqued in there between dissimilar metals. Heating the head to expand it or freezing the bolt to shrink it may loosen it up, but you still need to get a good grab on it. If the bolt is large enough and the broken bit is small enough, you may be able to purchase a good titanium bit and drill out the old bit and use a good extractor then. Or drill small holes in a line across the bolt and use a screwdriver?

The removal of broken studs and bolts is a task where there are few shortcuts. Often you'll only get one chance before the tiny area by which the offending part can be engaged is too badly boogered to continue.

And by "continue" I mean "undertake near-complete disassembly of the vehicle which is currently parked (in the paddock of a distant race venue/in a bad part of town/on the shoulder of an interstate/upside down and on fire)

It can be difficult to resist the urge to grab a drill and the classic left-hand twist type extractors and go to it, but consider this - if applying enough torque to cause a shear event didn't break the fastener free - something of 1/2 the diameter which causes the fastener to expand, thus being retained even more so won't do it either.

The tapered 4 sided extractors:

Actually work pretty well, but you have to free the bond between fastener and host. Heat is king along with penetrants and impact.

Generally I'll apply a MAPP gas torch, get it hot, and hose it down with AeroKroil:

Repeat a few time. Then when it's hot, hit it with a punch and a stout hammer a few times.

Then center punch it, grinding a flat on the end if necessary, carefully center drill it, and heat and Kroil a couple more times. Then heat it again, drive the extractor in, and use a die stock to apply the torque so the extractor remains aligned with the fastener. If it doesn't feel as though it'll budge before the extractor or grip will fail - you're probably right.

More heat and Kroil cycles, and be ready when the extractor fails to disassemble the entire car.

To remove broken taps/drills from the parts in which they're buried all Excalibur-like: OMEGADRILLS! are magic. Seriously!