Rusty Exhaust Flange

Suvorovo · 11-07-2022, 04:52 PM

Lots of threads on removing rusty bolts from the flange. My bolts look like the below image. After cutting them off, will using heat + impact hammer to push out the remaining studs damage oxygen sensors or risk breaking the exhaust manifold studs at the engine? There’s a rubber bushing supporting the upper exhaust I would think the force of the hammer would be absorbed.

If an air hammer can damage oxygen sensors or the exhaust manifold studs, can I safely hammer them out by hammer and chisel? I’d love to get some kind of press tool, if it exists please share! C-frame clamp press maybe?

How much would a shop charge for this to save me 5 hours of work?

Mentally preparing for my first clutch job.

View post on imgur.com

TheMidnightNarwhal · 11-07-2022, 07:00 PM

Just went through this myself installing downpipes on mine. Mine looked worse than that and at first wanted to cut and drill to but figured I'd give the extractor sockets below a try since it was on sale and was honestly was not expecting the results. It worked perfectly.

If you use air hammer IMO I do think you can damage O2 with vibrations, I had read some posts about it.

Suvorovo · 11-08-2022, 10:09 AM

Extractor socket will work on melted away threads? Did you just break off the bolt with that set?

I'll give that a try, if bolts break off ill try to press them out with a hefty C clamp.

TheMidnightNarwhal · 11-09-2022, 10:28 AM

Quote:

Originally Posted by Suvorovo

Extractor socket will work on melted away threads? Did you just break off the bolt with that set?

I'll give that a try, if bolts break off ill try to press them out with a hefty C clamp.

I was able to find a picture with one nut left to remove when I took them off, the ones on top are better looking to since it's furthest away from the road salt to give you an idea, you be the judge but yeah I was pleasantly surprised. My nut just came off smoothly. The threads aren't really on the end part of the stud so what you might think is melted threads isn't IMO. Of course I used penetrating oil as well and hit the nut a bit but didn't even use heat. My plan was to also hammer the studs out and use a bolt if I ended up breaking the stud.

Suvorovo · 11-12-2022, 10:09 AM

Just to confirm, are these the correct parts? They don't look right from the FCP EURO images. Maybe they're indexed incorrectly on realoem.

https://www.realoem.com/bmw/enUS/sho...diagId=18_0587

bolt - 07119906928:
https://www.fcpeuro.com/products/bmw...x3-07119906928

nut - 18301737774:
https://www.fcpeuro.com/products/bmw...10-18301737774

gasket - 18107549447:
https://www.fcpeuro.com/products/bmw...et-18107549447

Sethorion · 11-22-2022, 09:35 AM

I broke two of mine off. I ended up chopping them flush with a grinder before drilling them out and replacing them with some zinc flake nuts/bolts of the same thread spec. I think they're M8 but worth a check. That way if anyone ever needs to work on them in the future they can just use OE hardware as one might expect to do.

11-07-2022, 04:52 PM	#1
Suvorovo Lieutenant 254 Rep 502 Posts Drives: Broken e90 330xi 6MT Join Date: Feb 2022 Location: New Jersey iTrader: (0)	Rusty Exhaust Flange Lots of threads on removing rusty bolts from the flange. My bolts look like the below image. After cutting them off, will using heat + impact hammer to push out the remaining studs damage oxygen sensors or risk breaking the exhaust manifold studs at the engine? There’s a rubber bushing supporting the upper exhaust I would think the force of the hammer would be absorbed. If an air hammer can damage oxygen sensors or the exhaust manifold studs, can I safely hammer them out by hammer and chisel? I’d love to get some kind of press tool, if it exists please share! C-frame clamp press maybe? How much would a shop charge for this to save me 5 hours of work? Mentally preparing for my first clutch job. View post on imgur.com Last edited by Suvorovo; 11-07-2022 at 04:58 PM..
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11-07-2022, 07:00 PM	#2
TheMidnightNarwhal Major General 2657 Rep 6,290 Posts Drives: 11' 335is DCT Join Date: Jun 2015 Location: Gatineau, Quebec iTrader: (0)	Just went through this myself installing downpipes on mine. Mine looked worse than that and at first wanted to cut and drill to but figured I'd give the extractor sockets below a try since it was on sale and was honestly was not expecting the results. It worked perfectly. If you use air hammer IMO I do think you can damage O2 with vibrations, I had read some posts about it.
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11-08-2022, 10:09 AM	#3
Suvorovo Lieutenant 254 Rep 502 Posts Drives: Broken e90 330xi 6MT Join Date: Feb 2022 Location: New Jersey iTrader: (0)	Extractor socket will work on melted away threads? Did you just break off the bolt with that set? I'll give that a try, if bolts break off ill try to press them out with a hefty C clamp.
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11-12-2022, 10:09 AM	#5
Suvorovo Lieutenant 254 Rep 502 Posts Drives: Broken e90 330xi 6MT Join Date: Feb 2022 Location: New Jersey iTrader: (0)	Just to confirm, are these the correct parts? They don't look right from the FCP EURO images. Maybe they're indexed incorrectly on realoem. https://www.realoem.com/bmw/enUS/sho...diagId=18_0587 bolt - 07119906928: https://www.fcpeuro.com/products/bmw...x3-07119906928 nut - 18301737774: https://www.fcpeuro.com/products/bmw...10-18301737774 gasket - 18107549447: https://www.fcpeuro.com/products/bmw...et-18107549447
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11-22-2022, 09:35 AM	#6
Sethorion Enlisted Member 9 Rep 48 Posts Drives: 2010 E92 335i MSport LCI 6MT Join Date: Sep 2021 Location: Cheltenham, UK iTrader: (0) Garage List 2010 BMW E92 335i LCI [0.00]	I broke two of mine off. I ended up chopping them flush with a grinder before drilling them out and replacing them with some zinc flake nuts/bolts of the same thread spec. I think they're M8 but worth a check. That way if anyone ever needs to work on them in the future they can just use OE hardware as one might expect to do.
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