Thoughts on removing a exhaust manifold bolt

[banshee400]

Background, I'm swapping my 99 forester engine for a 2003.

 

We were unable to get one of the exhaust manifold bolts on my 99 forester off. But were successfull at stripping it so we couldn't remove it. We've tried using a torch to cut it but it won't cut. We've also tried a grinder but our compressor isn't big enough to allow us to cut on it for any length of time. Anyone know of something we haven't thought of? My thought is to leave it and work on it when it's out of the car.

[njdrsubaru]

use an electric grinder!

[beataru]

here if you have acces to a welder (mig) weld on a nut to the stud The END of the stud, But you need to get the stud hot so the bead will penatrate into it, then if you do a good job you can just stick a wrench on there and turn it. Hope it helps, SOMEONE YOU KNOW HAS A WELDER!!! buy them lunch and youve got it!

[86BRATMAN]

Try soaking it down with a good quality penitrating oil, none of this wd-40/ liquid wrench voodoo water. Pb Blater, Sea Foam Deep Creap, or Kroyl. Then put a vice grip on it and see if you can budge it that way.

[Kilroy]

here if you have acces to a welder (mig) weld on a nut to the stud The END of the stud, But you need to get the stud hot so the bead will penatrate into it, then if you do a good job you can just stick a wrench on there and turn it. Hope it helps, SOMEONE YOU KNOW HAS A WELDER!!! buy them lunch and youve got it!

 

 

I've been a welder for the last 11 years and can honestly say that there is no way to get a nut on the head of a bolt of this diameter that would be stronger than the original head. The trouble would be that any decent penetration would practically cut all the way through the bolt.

 

You can continuously soak it with good penetrating oil as previously suggested until the engine is out. Once it is out, cut or grind 2 sides of the remaining bolt head flat and get a wrench on it and lightly tap on the bolt head as you apply torque to the wrench. You can also cut a groove across the head and use a large flat bladed square stem screwdriver (the one that allows you to slide a 6mm wrench over the metal end) and tap on the head of the screwdriver while someone else applies torque to the wrench. If these fail, you may be left with cutting it flush and drilling out the bolt.

[johnceggleston]

I've been a welder for the last 11 years and can honestly say that there is no way to get a nut on the head of a bolt of this diameter that would be stronger than the original head.

 

i think this is a stud, not a bolt, no head. but you're point may be the same.

[beataru]

my dads friend who is a machinest (as probably stated above I forgot) just did this for me on my up-pipe to my turbo. I couldnt get the stud out so I cut it and started driling it with some cobalt bits, that stud was the hardest stainless I have ever seen ( it destroyed 3 bits and I was going slow and lubing it as if I had an auto luber set up) so I knew that He would have the bits to get it out, and he didnt even use bits, he just welded on a nut to the stud and vualla (is that how you spell it)

[eryque]

my dads friend who is a machinest (as probably stated above I forgot) just did this for me on my up-pipe to my turbo. I couldnt get the stud out so I cut it and started driling it with some cobalt bits, that stud was the hardest stainless I have ever seen ( it destroyed 3 bits and I was going slow and lubing it as if I had an auto luber set up) so I knew that He would have the bits to get it out, and he didnt even use bits, he just welded on a nut to the stud and vualla (is that how you spell it)

 

it's actually voilà with an accent over the a.

[beataru]

Well if we want to be critical here then FINE!!!

 

 

 

 

[Kilroy]

Ahhh, a stud. He said it was a bolt so I figured it had a head on it. My bad. I can see a stud having a nut welded on from the top and being plenty strong to get the stud out, it's been done plenty where I work. It's even easier with stainless as you can run a colder pass and stainless is much stronger than carbon grade steel. If you are trying to drill out stainless, try to find drill bits that are rated for cast iron. If they can drill cast iron, stainless will be no trouble at slow speed with cutting oil.

[beataru]

Get some High Density Cobalt bits!!!! or just buy about a million titanium coated bits!!!!!!!!!

[bulwnkl]

I agree with welding a nut on the end, though you certainly don't need a mig welder. I've done that countless times with a good old stick welder and it works just as well. Mig, tig, or stick will all work if you know how to use the welder well.

 

If you've already been grinding and/or trying to cut it off, though, you may still be unable to back it out (I don't know how much of it you've removed). A couple things I didn't see you having tried:

 

1) Use a hack saw. Yes, it'll seem like it takes you 6 months to do it. Yes, you may hear from some that a hack saw won't cut the stud (if it really is stainless, which would surprise me but maybe it is). Yes, you'll be so tired that you may think you can never use your arm(s) again. HOWEVER, a hack saw will cut it, even if it's ultra-hard. You will be able to use your arms again (eventually...). It will PROBABLY take you less than 6 months , and then you can drill it or whatever you want to do.

 

2) Heat it up REALLY hot. If it's carbon steel, it may very well need to be glowing bright red or orange. I wouldn't do this on an assembled engine, though, as you'll light it on fire (oil and fuel fire plus all gaskets and seals). Really, I wouldn't do this to an aluminum head at all because of the liklihood of warping it, but you asked what you hadn't tried . A good engine shop accustomed to heating heads and welding them or fixing valve seat issues may be helpful here. There's a great diesel engine shop in Spokane, WA, for example that I'd trust to do this.

[idosubaru]

okay i've had to do this a number of times and just recently did it to multiple bolts on an EJ25...very annoying, but i guess i'm getting good at it and hope my awful experience can help someone else. i think i even posted a thread about it. anyway...speaking from significant experience about what does and does not work:

 

welding a nut will work. actually what i also do is weld a steel rod to the stud and just use the rod as leverage. the result will likely be the same either way - if it's rusted and seized as bad as mine were, it will just shear the stud off though, but at least the exhaust manifold will come off that way and it makes removing the engine easier.

 

grinding will also get it off. and Cobalt drill bits are the way to go.

i used all three of those methods to get the ones off i had to deal with.

 

do not waste your time, money or effort on anything else than the methods listed above.

[johnceggleston]

if the studs as stuck as as suggested this will probably not work, but since i don't weld... i'd try re-tapping the threads on the stud, put on some nuts and then try to remove. they don't even have to be metric. of course the double nuts might just strip the threads again and you have to weld anyway, but this would be my first try.

[idosubaru]

the problem with that is they are usually stuck due to corrossion and rust. which is usually also attended by very poor threads. most of the time the threads protruding beyond the nut are nearly non existent and really don't take a nut at all. if they do they are typically very loose and won't take much force at all.

 

welding, grinding and drilling are your only options for really bad ones. if they come out any other way, they're not that hard to get off. with bad ones (and i mean bad), you're really trying to get something on there solid enough to shear the bolt, they will not come out of the block at this point. and you're not going to shear the bolt with wrenches/vise grips.