Living in California our biggest problem is exhaust nuts and bolts ,
But if I was in the rust belt and had to fight half the nuts and bolts to get them off I would think $400 for the bolt buster is a deal if I did not have to drill and tap 20 broken bolts over a few years...
But I would love a DIY setup and maybe just buy the "probes" from Amazon
noddaz said:
This is better than no heat at all. (If you have one.)
I hit the nuts hard with a MAP gas torch, 7-10 cycles of getting them "softly glowing" hot, letting them cool. I also hit them with PB Blaster JUST after heating them. (Know what smells worse than PB Blaster? Vaporized PB Blaster.) Nothing made any difference. I'm going to drill/dremel the nuts. As a backup I ordered the BMW specific $16 each exhasut bolts. (PB Blaster fumes got to me, I guess.)
We're leaving for family Christmas Friday, so this will have to wait until the 30th, which is great, since it will be even colder then. The annoying thing is, the exhaust is in great shape, like not a mark on it, it's just in the way of a part of the driveshaft I need to get to.
mad_machine said:all these posts and not a single mention of the lowly Nut Splitter?
Ha! That was my first thought, but the nuts on the flange are so close to the exhaust pipe that there is no good way to get any of my circular splitters in there. I thought about ordering one of those "s bend" splitters off Amazon, but for that I might as well just dremel...
In reply to Dave M :
I applied break free lube liberally (pb blaster and waited like you are supposed to).... didn’t work but they got my money.
Then I used my 1/2 “breaker” bar and went to work “breaking” those rusty pieces of e36 m3.
I’m putting new mufflers in the same car soon too. I needed new cats to pass emissions. It’ll sound superb soon. I bought new hardware for the mufflers.
My vote is for AngryCorvair’s method or #1, then #3. Sometimes it’s not worth the headache, just pay the man. Personally I think an unheated garage at 35-40F is an asset in this case, since this is going to be a sweaty cuss-a-lot type job anyway.
ManhattanM (fka NY535iManual) said:
The annoying thing is, the exhaust is in great shape, like not a mark on it, it's just in the way of a part of the driveshaft I need to get to.
Every modern BMW seems to do this. My E39 had seen around 13 or 14 New York winters when one of the gaskets joining the headpipes to the intermediate pipes decided to call it quits. The studs and nuts were almost indistinguishable as such, but the rest of the exhaust was still nice and silvery under a fine layer of dirt.
I strongly recommend a nice thick layer of anti-seize on the new hardware.
Dad never got a chance to pass too much knowledge, as he passed early in life, however there was one thing he did pass on - exhaust work is why shops exist. . . . . . . . .
Going to take the bait......
And how would a shop do it ? Some special tool that we do not have ?
Or a lift so they can stand up and do the work.......
I need to replace the exhaust manifold on my old Nissan truck and would love to not break any bolts !
Lift and doing it standing definitely makes it a bit easier for a shop, especially as far as being able to use destructive tools on the bolt/stud/nut without collateral damage. And some of it is just the guy who does it 10 times a day vs once every few years kind of thing that makes it easier for them.
02Pilot said:ManhattanM (fka NY535iManual) said:The annoying thing is, the exhaust is in great shape, like not a mark on it, it's just in the way of a part of the driveshaft I need to get to.
Every modern BMW seems to do this. My E39 had seen around 13 or 14 New York winters when one of the gaskets joining the headpipes to the intermediate pipes decided to call it quits. The studs and nuts were almost indistinguishable as such, but the rest of the exhaust was still nice and silvery under a fine layer of dirt.
I strongly recommend a nice thick layer of anti-seize on the new hardware.
Auto exhaust and emssion engineers high five each other. Pipe integrity maintained and bolts fail safe to become rivets!
Has anyone had success with a exhaust bolt and nut replacement innovation?
Dont be bitch. Cut em.
In reply to AnthonyGS :
Nice work! I'm impressed.
In reply to Dave M :
Well I'm old enough now and have been wrenching on the side long enough, I don't give up until the job is done. I know what shops do and how they will approach such things, so it's usually better if I find a way. Thanks for the compliment; they were pretty small bolts. I'm surprised Germans put regular carbon steel fasteners on their exhaust. I figured they'd have used stainless, anyone buying their cars pays stainless prices.
In reply to AnthonyGS :
Stainless has some significant limitations for fasteners (in the form of galling as well as being much weaker than the higher grade steel bolts). I've heard of inconel ($$$) being used for exhaust bolts to avoid corrosion, however. And BMW often used copper nuts on the bolts in hopes of the nut and bolt not permanently rusting together (but eventually it all corrodes to crap anyway).
In reply to rslifkin :
Yep, the factory spec replacements for the 4 studs that are the bane of my existence ATM are inconel bolts, $16 each. Each. If I only end up using one of them to replace the already broken stud, it will be interesting to check back in a couple of years to compare, literally side by side, how the different materials hold up.
I often drill out the studs with malice (who cares about threads) and replace it with a bolt/nut. That will only work on some manifolds, though depending on what the shape of the other side of the flange looks like.
In reply to skierd :
I’m glad *someone* read my post. Tool recommendations, detailed description of how to do it, and photos of results. Could almost put a “/thread” on it.
In reply to AngryCorvair :
I read it also, novel approach to a miserable situation. Thanks for sharing!
I spent almost four decades working on cars in the rust belt including a short stint in an exhaust shop. I solve most rusty exhaust issues with an oxy-acetylene torch. With fasteners, if heating the outside threaded part cherry red isn't enough to make it fastener loosen up then I just cut it off. With some practice nuts can be cut off of bolts bolts or studs with an oxy-acetylene torch without damaging the male threads. Studs can be burned out of manifolds while leaving enough material to run a tap in and salvage the threads. Pipes can be cut inside or outside without damaging the mating part.
Yes all metals have their benefits and strengths in use for fasteners. I still can't believe Porsche didn't at least galvanize the hardware. Stainless isn't a perfect material but it's a lot better at heat and corrosion than low carbon steel. I could dig up my materials book and spec something better than many select. The bean counters at every auto maker get the final say though, and that is what makes this hobby more challenging.
For those who like closure:
Before I could tackle the exhaust again, in Jan of last year I started a new gig that unexpectedly ended up involving travel like 60%+ of the time. I only put 1,150 miles on this car in all of 2019...to prevent divorce, I ignored the driveshaft vibration and broken stud until *this* weekend. I overnighted the 3 remaining studs with PB Blaster, and the next day got them to cherry hot with MAP. 2 nuts came off using a cordless impact wrench to help vibrate them off. I chose safety over bravery and split the nut on the last one using AngryCorvair's technique. (Thanks AngryCorvair!)
On the broken stud: I cut it flush with a dremel cutting wheel, drilled into it a ways, then used a dremel cutting bit that's almost like a router to remove enough of the material to tap the stud out with a center punch.
I have taken 4 showers and still smell like burned PB Blaster.
In reply to ManhattanM (fka NY535iManual) :
Hooray!
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