Exhaust Bolt Troubles

[jaekormtb]

I was installing headers on my 1999 986 and managed to have a manifold bolt head break off. UGH! Anybody have experience drilling these things out...or any other suggestions for getting the end of it out?

Just for info, I aborted the header project when the bolt broke and simply checked the torque on the rest of the manifold bolts and put everything back together. No exhaust leaks so far...

[navin in KC]

I was installing headers on my 1999 986 and managed to have a manifold  bolt head break off. UGH! Anybody have experience drilling these things out...or any other suggestions for getting the end of it out?

Just for info, I aborted the header project when the bolt broke and simply checked the torque on the rest of the manifold bolts and put everything back together. No exhaust leaks so far...

<{POST_SNAPBACK}>

I've broken a number of bolts off in cars in the past, mostly my 1966 Mustang.

Most part stores have what my dad calls an "Easy-Out", which is a misnomer.

You drill out the center of the bolt, then put the easy out into the hold and turn it, usually by hand. It has reverse threads that grab the bolt and unscrew it. I'd soak that bolt with penetrating oil a number of times before you drill it.

Good Luck.

[MNBoxster]

Hi,

Is the bolt broken at the head, flush with the surface of the head? If so, as mentioned an 'Easy Out' is likely your best bet. If the bolt shaft is broken below the head surface, you may not be able to use the 'Easy Out' because drilling the bolt shaft could damage the tap in the Head. You need to be VERY careful in drilling the broken bolt shaft. Make sure you use a starter punch and align it squarely on the bolt shaft. If you don't, there a high likelyhood that your drill bit will wander and take out the threads in the Head.

If you screw it up, it'll cost $$$$. You will likely need to helicoil it and this could be somewhat tenuous given the location, high-temp environment and the torque value. Unless you have a lot of experience (and no offense, it doesn't sound like it, just from the nature of your post), since the car runs, I'd suggest having this done at a shop. I think you'll be better off.

Happy Motoring!... Jim'99

[adsach]

Hi,

      Is the bolt broken at the head, flush with the surface of the head?  If so, as mentioned an 'Easy Out' is likely your best bet. If the bolt shaft is broken below the head surface, you may not be able to use the 'Easy Out' because drilling the bolt shaft could damage the tap in the Head.  You need to be VERY careful in drilling the broken bolt shaft.  Make sure you use a starter punch and align it squarely on the bolt shaft.  If you don't, there a high likelyhood that your drill bit will wander and take out the threads in the Head.

      If you screw it up, it'll cost $$$$. You will likely need to helicoil it and this could be somewhat tenuous given the location, high-temp environment and the torque value.  Unless you have a lot of experience (and no offense, it doesn't sound like it, just from the nature of your post),  since the car runs, I'd suggest having this done at a shop.  I think you'll be better off.

Happy Motoring!... Jim'99

<{POST_SNAPBACK}>

How about drilling or burning out the sheared studs with a torch and putting in bolt/nut combos? <this is a question-not a suggestion>

It has been my experience on american cars that ALL header bolts and studs break as the heat advances rust and destroys the threaded rod. Extremely rusty exhaust bolts (unlike say headbolts), not only snap but tend to 'weld' themselves into place so that easy out techniques don't seem to work. The boxster seems to be no different.

There is ample space and access for bolt/nut sets. Replacing a stud with a stud, especially after helicoil, pretty much guarantees you will break it again next time you need to take apart the system.

This has to be one of the most common problems seen by a muffler shop, what do they usually do? Cut off the flange?

[adsach]

Now that I reread your post, I can see that I was picturing the exhaust pipe end of the headers, not the block end. I'll amend my suggestion and defer to having the studs loosened and repaired as needed by a reliable shop.

Any one have any suggestions about what to do with snapped bolts at the triangular flanges for the exhaust? (I have 2 broken off)

[MNBoxster]

<{POST_SNAPBACK}>

How about drilling or burning out the sheared studs with a torch and putting in bolt/nut combos? <this is a question-not a suggestion>

It has been my experience on american cars that ALL header bolts and studs break as the heat advances rust and destroys the threaded rod. Extremely rusty exhaust bolts (unlike say headbolts), not only snap but tend to 'weld' themselves into place so that easy out techniques don't seem to work. The boxster seems to be no different.

There is ample space and access for bolt/nut sets. Replacing a stud with a stud, especially after helicoil, pretty much guarantees you will break it again next time you need to take apart the system.

This has to be one of the most common problems seen by a muffler shop, what do they usually do? Cut off the flange?

<{POST_SNAPBACK}>

Hi,

While this sounds counter-intuitive, there is a big difference between using a Bolt and a Stud/Nut combinaton. You may be aware that all threaded fasteners are elastic. Applying a specified torque to the fastener stretches it and this is what holds it in place (if not, vibration would simply work it loose over time). The Bolt imparts this stretch over the entire length of it's threaded shaft, which a Nut will not do. Especially for something as torque sensitive as an exhaust seal, the Bolt is the fastener for the job.

So far as using penetrants, I recommend 'PB Blaster'. Unlike a traditional penetrating oil, 'PB Blaster' contains enzymes which literally 'eat' the corrosion away in addition to lubricating the fastener. This would be especially helpful on an exhaust fastener. Use it liberally and let it work for 24 hrs. or more, reapplying a couple of times, no heat or you kill the enzymes. Then, you may find an 'Easy Out' will work just fine.

"A man's got to know his limitations" - Clint Eastwood (Magnum Force - 1973). If you believe you are capable of properly drilling the broken Bolt Shaft to accept an 'Easy Out', by all means give it a go (after a thorough soaking w/ 'PB Blaster' as mentioned above). If not, then let the pros do it - it'll be cheaper in the long run.

Happy Motoring!... Jim'99

[jaekormtb]

PB Blaster sounds like the info I was looking for. I've got a set of EZ outs and I've used them before. Looks like I'll be using at least one of them again. Just in case, I was wondering how much metal there is in the head. Is there enough to bore/retap and use a larger bolt? Most of the work I've done has been on Chevy heads- on those there are a few spots that come close to water jacketsand shouldn't be drilled but so much. By the way, the bolt that broke is center front outside on the left cylinder head.

[Tool Pants]

Any one have any suggestions about what to do with snapped bolts at the triangular flanges for the exhaust? (I have 2 broken off)

<{POST_SNAPBACK}>

If it is like this then a BFH.

http://www.renntech.org/forums/index.php?s...ic=1006&hl=stud

[adsach]

Any one have any suggestions about what to do with snapped bolts at the triangular flanges for the exhaust? (I have 2 broken off)

<{POST_SNAPBACK}>

If it is like this then a BFH.

http://www.renntech.org/forums/index.php?s...ic=1006&hl=stud

<{POST_SNAPBACK}>

Thanks.

Which seems like the riskier plan... leave it in the car and swing a 3lb sledge at it and possibly break studs holding header to the clyinders at the other end.

or

remove the header to swing at it in a bench vise and possible snap the studs holding header to the clyinders while trying to remove the header.

BTW - what is the torque to reinstall the header (2002 S)

[Tool Pants]

I asked Peter how how removes a broken stud on the exhaust flange.

He pounds it out but supports the back of the flange with a large hammer. Does not use heat. I did not ask but I assume it is best to do this with 2 people.