Exhaust stud removal tips?

[reclino]

I have soaked these in peneyrant oil for months, heated them up, and tried welding nuts onto them. I got 6 out, but 6 are stuck fast.

[reclino]

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[reclino]

I have never had this hard a time removing exhaust studs. I thought the heat from welding the nuts on would get them loose. But they seem stuck fast, and they are getting pretty close to the head.
I may need to buy a drill out kit.
David

[fred cook]

If you can get a propane or mapp torch flame in the exhaust port, heat the metal right next to where the stud is screwed into the head. This will melt the thread locker and let the stud come right out. You may have to experiment with the amount of heat needed. I used this method on a set of Carrera heads that needed longer studs to be installed. Worked like a champ! Good luck!

[Jose_JGC]

About 6 years ago I had my 1970 911T's heat exchangers replaced at a Porsche specialized shop. I watched from a distance as they had a hard time removing 3 of the studs. They had to drill out these, swear a couple of times and then clean/redo the thread with a tap. There are no exhaust leaks, so I it was a job well done.
I wish I could give you more info.
Jose

[Steam Driver]

Actually, it's not a given that you have to heat the head around the stud. Using the mapp or propane torch heat the stud red hot, then let it cool off and try to remove it, using either your welded on nut or a bona fide stud remover like the Snap-On 500 series.

What happens when you do this (Heat the stud) is that the stud swells in the hole, expanding it somewhat, so that when it cools off the hole is slightly looser and any chemical and/or corrosive bond is broken. I learned this technique working at a place where we deal with a lot of rusty fasteners, albeit on a much larger scale - a railroad museum. Using it I removed and replaced all of the exhaust studs on my SC with no problems at all.

[cgarr]

You can drive the stud into the head with a few good blows, shock it loose, most times comes right out but don't be mild with it you really have to hit it,

[reclino]

I have tried hitting it with the BFH. That didn't work yet.
David

[Dpmulvan]

If you have to get a dremel with a cutoff wheel and cut them off. Sometimes they just won't let loose and you"ll have to buy a drill out jig. I just did mine a few months ago and had to cut a few off. Also an impact wrench with a short 6 sided swivel socket might help you.

[3literpwr]

I did this on a bench and still broke a number of them. In the end, they needed to be drilled out and have inserts installed.

[reclino]

I tried heating the head with a propane torch for 20 minutes last night and snapped another nut off.
David.

[djb25]

I just did this a few months ago.

I had tried to do it about five years ago, and gave up after breaking three studs in a row. I bought a drilling jig, but even that is a pain in the ass.

This year I used a MAPP torch and did the "heat inside the exhaust port" trick. Every single one came out! It's weird, but there is a very short window for them to come out. If I waited any amount of time after the torch, they were stuck fast. But once I found the sweet spot, they would come out without any trouble. I didn't heat the studs at all, just the head.

To remove the studs I used a metric stud remover I got on Amazon. Not anywhere near as nice as the snap-on type, but way better than the "hammer-on" Irwin type, or the gigantic cam-style.

[safe]

If you haven't tried an impact then weld on another nut and try that. I have with success used a cheap electric one because I lack a big compressor.
Heating the exhaust port right prior will also help.

[Spenny_b]

If all else fails, get 'em spark eroded out.

When I first bought my car, it was knowing that there was a snapped stud on #3 - the chap I used to do some initial work on the car happened to be local to a place who specialise in getting these problems sorted - the expert in the workshop, never to be introduced to a customer (he was a little "strange"), was an absolute genius apparently. Spent a lot of time getting studs out of vintage motorbikes and dancing donkeys, which are apparently worse still than some of our stuff. They used to charge, iirc, about $50-60 per stud. Because they can.

[reclino]

I have an electric impact gun and have tried that as well. Same result. I am letting them sit for a while longer until I have more time to go out and play.
David

[Bird911]

I also did broke one of my exhaust stud flush with the head while trying to remove it. I first drill the stud and tried with a square extractor but without success. I moved to plan B and dissolved the stud with a 50/50 mix of concentrated nitric acid and water. The acid only was not reacting, you need to add water. It took me a couple of hours, putting the solution in the extractor hole and letting it work for 15-20 mins periods, and then taking it out with a syringe. I first did a test with aluminum paper and a piece of stud in a glass to make sure the aluminum was not harm. Everything went well, but make sure you also do the test and wear protective gear.

[Spenny_b]

Originally Posted by Bird911

I moved to plan B and dissolved the stud with a 50/50 mix of concentrated nitric acid and water. The acid only was not reacting, you need to add water.

Walter? Walter White?....is that you?

[reclino]

Walter White preferred hydrofluoric acid.

[Bird911]

Originally Posted by Spenny_b

Walter? Walter White?....is that you?

Yes, I am the one who knock !

[RD911T]

Any luck with this? I bought an exhaust stud jig made by a member here and it worked great for the 2 studs I needed to drill out on my 3.0L. PM me for contact info or I'll loan you mine as long as we can insure I'll get it back.