Broken exhaust stud- suggestions?

I like PB Blaster as a penetrating oil.  I'd think heating around the broken stud would break the hold?  Seems I've always ended up drilling them out and using a helicoil threaded insert but mine were always broken off flush.  Not fun.

Grind the stud face even, tap it with a hammer to see it that is enough to shock it loose and be able to turn it. Then center punch it drill it out starting with a smaller bit. A couple things may - will happen , the heat from grinding ( it you have enough sticking out, you can grind it until it glows red) that may be enough to loosen it as well as shocking it with a center punch.

Thanks for the reply. I used PB blaster for a few days, then switched to Crown 6030 for the last couple days. Only because I had it and it also has good reviews....

Use an easy out to remove it. You can buy a kit of easy outs that will include a size to pull this stud out after drilling a proper sized hole in the center of the stud. Drilling the stud out places you in danger of wiping out the threads and then you will need to install a threaded insert Heli-coil. Good luck whichever way you proceed. Many of us have been right where you are.

Thanks for the replies,

I'll be attempting later this morning, am just nervous because I don't want to screw it up.

When you replace the stud,  coat the threads with nickle((?) based neversieze…..  good to over 2500 f. I believe……. Copper based compounds have been used, but I’ve never seen nickel fail at 2000f. utilizing dissimilar metals in tempering furnaces….

And use the copper nuts when replacing exhaust nuts. About $8 for 8.

I've never had great luck with easy outs - break one off and you are in a world of hurt as they are near impossible to drill.

@Jimmy V. posted:

Use an easy out to remove it.

The devil doesn't carry a trident - it's an "easy-out" (which is a complete misnomer).

Easy-outs were invented to give false hope to the truly hopeless, so that the home mechanic might delude himself that there's some alternative to just removing the part and taking it to a machine shop.

Assuming you can hit the exact dead-center of the twisted off piece of hardware with a drill (you can't), and you can drill a perfectly straight hole right down the center (you also can't), and that you can keep from breaking off the drill-bit in the off-center hole you just drilled (ditto) - the tool will either not bite in the hardware (creating a nice chamfer in your off-center hole), or twist off when you try to use it.

When this happens, you may want to just find a piece of handy rope and hang yourself. It'll be easier than dealing with the mess of a hardened tool inside a hardened bolt stuck in a piece of Aluminum. Fire is also an option - either the car or the entire shop, depending. I recommend against immolation, there are easier ways to go.

In the event that you decide you still have something to live for, you can just remove the head and take it to the machine shop... just like you could have before you started, spent an entire weekend on your garage floor thinking bad words, cutting your knuckles, and ruining about $50 worth of drill bits, etc.

Good luck.

Phooey.. reread my post I have always had god luck using my methods :~)

@Alan Merklin posted:

Phooey.. reread my post I have always had god luck using my methods :~)

I agree, Al. I've always had the best luck with a very similar approach. I've just had ZERO luck with easy-outs. I threw every one of mine away.

Your mileage may vary.

I've always had good luck with a hand impact tool, the one that breaks things loose when you hit it with a hammer.

It works pretty good on oil-relief plugs on mag cases. And VW-Porsche rotor screws.

But yeah, repeated application of Nuts-off or penetrating oil(always favored Liquid Wrench), like every day for a week.

Then the fire hammer almost always works.

The only easy outs I've ever used with any success are the square tapered ones. Drill the required hole, drive in the easy-out with a hammer and unscrew with two small wrenches opposing each other or use a tee handle with the right size square socket.

Heat is a friend here. Not too much and not too little

I view easy outs as a short-cut first alternative to  (in this case) removing the head. Sometimes you just have to bite the bullet and go to a machine shop if you don't have the tools at home.......Bruce

I also tried heating the stud with oxyacetylene until glowing red. When I tried to turn the double nuts, it stripped the couple threads that the second nut was held on by.

So I'm going to try Dr. clocks way, and if that doesn't work I'll weld a nut to what's left of the stud?

I as well have never had success with easy-outs.  Welding a nut onto the offending stud is supposed to work great- I'm guessing the heat does the work and breaks the hold.  I have also been told that after bathing repeatedly in penetrating oil, a couple of heating sessions and smacking with the hammer that left handed drill bits have a good success rate (if you don't have welding equipment handy), turning the stud out when you get close to the threads.  I haven't had cause to use any of my newly bought set yet so I can't attest to their effectiveness, but a couple of friends have said to start with a solid defined center punch hit, then a small drill bit and moving up in size as needed.

@Tac422 posted:

I also tried heating the stud with oxyacetylene until glowing red. When I tried to turn the double nuts, it stripped the couple threads that the second nut was held on by.

So I'm going to try Dr. clocks way, and if that doesn't work I'll weld a nut to what's left of the stud?

The heat was supposed to be applied to the head, not the stud. I don't think anyone mentioned that.

Welding a nut on works. I once welded a coupling nut onto a broken wheel lock. That one came off then the whole wheel lock set of 4 went into the bin!

I’ve had much better results than PB Blaster or other penetrating oils by mixing up a 50/50 batch of auto transmission fluid, like Mercon but any cheap ATF will work, and acetone.  Spray or drip it on like everything else and wait.  Re-apply 2 or 3 times over an hour and then try backing the stud out.  I usually use vice grips on it but a welded on nut is great.  Exhaust studs are the worst because the heat accelerates the chemical process between the aluminum head and steel stud and often no penetrating fluid will break them loose.  Then, heat seems to be your only alternative.

@DannyP posted:

The heat was supposed to be applied to the head, not the stud. I don't think anyone mentioned that.

Welding a nut on works.

The idea, as Danny said, is to heat the area surrounding the stud/bolt to expand it. However, heating the fastener, then spraying it with a penetrating oil at the root of the joint will often get the PB Blaster (et al) to suck up in the threads. I spray it and keep spraying until most of the can is gone, then I get out the Zoom-Spout oiler, or some 3-in-1. You're trying to free the corrosive bond between the stud/bolt and whatever it's going into. Expanding the FM threads is best, but if all you can do is expand the male threads, heat the stud and then let it cool a couple of times, spraying penetrating oil liberally, and it'll often be enough.

But to the quoted text, almost every time I've welded a nut on a stud, the stud gets much hotter than it did by simply heating it, and it's either twisted the bolt/stud off flush, or backed it out.

Either way, you've got nothing to lose.

@ALB posted:

Welding a nut onto the offending stud is supposed to work great- I'm guessing the heat does the work and breaks the hold.  I have also been told that after bathing repeatedly in penetrating oil, a couple of heating sessions and smacking with the hammer that left handed drill bits have a good success rate (if you don't have welding equipment handy), turning the stud out when you get close to the threads.  I haven't had cause to use any of my newly bought set yet so I can't attest to their effectiveness, but a couple of friends have said to start with a solid defined center punch hit, then a small drill bit and moving up in size as needed.

... which as I reread the thread is almost word for word what Al said (^). So yeah, what Al said.

@Stan Galat posted:

I agree, Al. I've always had the best luck with a very similar approach. I've just had ZERO luck with easy-outs. I threw every one of mine away.

Your mileage may vary.

Same here. I never had good luck with the fluted type easy outs, but I have a splined set that work like gangbusters.

For a stud, I’d probably use these if there was enough left protruding to get a grip on it.

My father was a top tier perfectionist Tool & Die Maker ( pre CNC ) He did not allow me or the human race to deviate from his God given knowledge of Metallurgy. I was never able to work with him without being berated at length .... Hence many a long day.  I got two things out of this relationship: I did learn quite a bit that got me straight A's in 9th grade Metal Shop and most importantly not to do anything with my kids with that same "genre"..... at times I had to catch myself.

@Alan Merklin posted:

My father was a top tier perfectionist Tool & Die Maker ( pre CNC ) He did not allow me or the human race to deviate from his God given knowledge of Metallurgy. I was never able to work with him without being berated at length .... Hence many a long day.  I got two things out of this relationship: I did learn quite a bit that got me straight A's in 9th grade Metal Shop and most importantly not to do anything with my kids with that same "genre"..... at times I had to catch myself.

I worked for Tool & Die Maker (also pre CMC) for a couple of years and have a small inkling of what you mean. I've never met anyone who was more of a perfectionist.

If you get it to break free and move, work it back and forth in both directions. SLOWLY. It should back out

Thanks for all the suggestions. I'm currently hitting it with PB Blaster a couple times a day while planning my next move.

@Tac422 posted:

Thanks for all the suggestions. I'm currently hitting it with PB Blaster a couple times a day while planning my next move.

I think that would be my approach, too.

Leave the car in the garage when you move and let the next owner deal with it.

Got it !  I've been spraying the stud with PB a couple times a day and heating the head up with a torch. Also used a centerpunch on the face of the stud.   I figured I'd give it one last try before welding a nut on the stud, and broke it loose while trying to tighten (not loosen). I then moved it back and forth and eventually got it out. I will be using the good never-seize and copper nuts upon reassembly.   

Thanks for all the advice and suggestions !

Glad you got it!

FWIW, I saw a YouTube video a year of so ago where someone tested the properties of all the “nut-buster” formulations (except Kroil, which a lot of people swear by)

As a recent convert to ATF/Acetone after a lifetime of PBlaster, I was surprised that all were bested by Sea Foam DeepCreep, in both penetrating and anti-corrosion.

@Tac422 You might run a tap in and out too clean out the treads also.

@Tac422 posted:

Got it !

Huzzah!

Victory, sweet victory.

Every time I have checked this thread I have been hoping to see a happy conclusion.

I'm glad we finally got there!