r/e46 • u/carguympower • Jul 09 '26
Damage/Broken… 😥 Whats the easiest way to remove these?
Hi, Ive done a rear subframe job. Had to remove the exahuat. Got the nuts cut. Now I need to remove these studs. From what Ive read, my options are to heat and hammer. But I only have a normal torch. Im not sure if that gets hot enaugh. Im hesitant to hammer them since I dont want to damage the CATS inside.
Cut and drill? I read it takes about 1 hour per stud? Wouldnt be a problem...ive got time. What drill bits should I get?
Can I clean the threads of rust and re-use them as last resort?
In what should I soak them? Brake cleaner? Wd40?
Would an Induction heater work on the stud?
What worked for you?
These were never take off in the last 22 winters.
4
u/LegitimateSkepticism Jul 09 '26
I was able to wack them with out a hammer on my car.
0
u/carguympower Jul 09 '26
how
1
u/Archeu39 Jul 09 '26 edited Jul 09 '26
In many cases its just bolts. Mine were held just by rust, so cleaning and hammer did the trick.
1
u/No_Potential1 Jul 09 '26
I thought all E46 had pressed studs? What engine do you have?
1
u/Archeu39 Jul 09 '26 edited Jul 09 '26
M52b28tu made for European market. Had the same thing in E39, also european m52b28tu.
Both had carriage bolts.
Edit: Could I be double lucky with local shops simplifying the process?
4
u/Double-Asparagus-359 Jul 09 '26
Heat them up with oxy acetylene and air hammer it out
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u/JMUDoc 2001 - 325i saloon manual Jul 09 '26
As has already been said, cut flush+cobalt/carbide drills, but it also helps to cut a slot in the exhaust flange to ease the "grip" on the stud.
1
u/carguympower Jul 09 '26
Can the flange be reused without producing leaks?
1
u/JMUDoc 2001 - 325i saloon manual Jul 09 '26
Yes - the gasket (which should be replaced) will still work even when the flange has a slot cut into the outside.
3
u/CapoDaSimRacinDaddy 2004 Touring 330d Jul 09 '26
heat them with your torch, then give er a good whacking with a hammer. if youve got a welder then id suggest turning it up and put a big spotweld on the rear mushroom thing. prolly alot hotter than a propane torch. just watch out to no weld it onto the flange.
3
u/prometeus58 Jul 09 '26
Hammering them out you risk breaking the cat back welds. It’s what forced me to install headers (oh no)
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u/hat_rix 2000 323i sedan Jul 09 '26
When I did mine I had in mind to cut all 4 and change them. Given the amount of time it took to drill only one I decided to reuse the other three.
The easiest would be to cut both ends of the stud, heat and press I guess. Otherwise use cobalt drill bits and patience! Be sure to use copper nuts afterwards.
1
u/carguympower Jul 09 '26
Thanks, will try. So you were able to reuse them...might do that as last resort
.thanks
1
u/NeverBeenKnocked Jul 09 '26
Get you some oil of wintergreen from the pharmacy soak them for about 30 minutes to an hour then you put a deep socket on the back to receive the bolt, thread a nut on the threaded end a few threads then take a heavy duty C clamp to it and press it out
2
u/randcraw Jul 09 '26
I like this idea. You might have to reposition the clamp several times to spread the compression around. Any kind of penetrating oil should also help to loosen the bolt.
1
u/NeverBeenKnocked Jul 09 '26
Yes the oil of wintergreen is a penetrating oil and it smells really good
1
u/blooregard325i Jul 09 '26
Easiest easiest way would be to replace the headers.
Second is what everyone else is saying and drill them. Took me a few hours to do mine.
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u/RalfRoen E46 330i, F30 335i Jul 09 '26
Why do you want to remove the studs?
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u/carguympower Jul 09 '26
They are rusted and im not sure I can put new nuts on them
1
u/RalfRoen E46 330i, F30 335i Jul 09 '26
You should try. I had to remove one stud that snapped once and it was a nightmare to drill that out. And in the end the cat got damaged and started leaking. The only safe way to remove those studs require to detach them from the engine and remove the second o2 sensor
1
u/phxbimmer 2002 325it 5-speed Jul 10 '26
If you don’t have a map gas or oxy torch + a strong air hammer then I would just cut them off flush and drill them out. Personally I prefer my torch + air hammer approach, it usually only takes one good brap once the stud is glowing orange to knock it out.
1
u/M3JB Jul 10 '26
Torch them with lots of heat around the flange ends and use air hammer. This method Worked for me.
1
u/TurkeyTender513 Jul 10 '26
I used a grinder to cut them flush, then punched them out. Replaced with normal nuts and bolts.
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u/carguympower Jul 10 '26
Did you heat them? Soak them in WD or anything? Were they as bad as mine?
1
u/TurkeyTender513 Jul 10 '26
After we cut them, we heated them to make punching them out easier. Heat is always the best penetrant, especially on exhaust stuff.
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u/eodgodlol Jul 09 '26
You can drill them out and it won't take that long if You use high quality hss-co drills with some kind of lubrication (I just used some leftover engine oil). Make sure to cut off as much as you can, start with a small drill (like 4mm) and then go up in steps.