Midpipe flange stuck to header pipe

cmichaelo · 10-09-2016, 07:11 PM

I'm replacing the midpipe on my 2011 E92 M3 with an ESS HFC crosspipe.

I had no trouble getting the bolts off the flanges. The flange on the header pipe is loose while the flange on the midpipe is welded into place. So this is all good.

The problem I have is that the midpipe's flange is stuck (siezed) to the header pipe itself. I've hit the midpipe a few time gently (so far) close to the flange with a hammer to see if it would break loose. But it's not budging and I'm not sure how hard I should hammer on it.

I'm soaking it in PB blaster overnight. But come tomorrow morning, any advice on how I should proceed?

The car has been exposed to the upstate NY weather for 4.5 years. FWIW, the clamp bolts at the midpipe-to-rear exhaust joint had to be hacksawed off. Further, the two bolts connecting the midpipe to the asymmetric bracket also sheered right off. So there's a fair amount of rust on this car, just to give you an idea of how bad the situtation might be at the headers as well.

FMLYSDN · 10-09-2016, 09:50 PM

Perhaps a torch. Heat it up. Try banging it then?

pbonsalb · 10-09-2016, 10:17 PM

Support the front end of the pipes near the headers. Go to the rear of the midpipe, wiggle a few inches side to side while pulling.

cmichaelo · 10-11-2016, 07:49 AM

I got it off. Overnight PB blaster broke loose rigth side. A little more gentle banging on left side and some wiggling of the pipes from the rear got the left side loose. Thanks for your advice.

10-09-2016, 07:11 PM	#1
cmichaelo Second Lieutenant 46 Rep 221 Posts Drives: '10 E92 M3, '22 Toyota Rav4 Join Date: Oct 2009 Location: Peekskill, New York iTrader: (0)	Midpipe flange stuck to header pipe I'm replacing the midpipe on my 2011 E92 M3 with an ESS HFC crosspipe. I had no trouble getting the bolts off the flanges. The flange on the header pipe is loose while the flange on the midpipe is welded into place. So this is all good. The problem I have is that the midpipe's flange is stuck (siezed) to the header pipe itself. I've hit the midpipe a few time gently (so far) close to the flange with a hammer to see if it would break loose. But it's not budging and I'm not sure how hard I should hammer on it. I'm soaking it in PB blaster overnight. But come tomorrow morning, any advice on how I should proceed? The car has been exposed to the upstate NY weather for 4.5 years. FWIW, the clamp bolts at the midpipe-to-rear exhaust joint had to be hacksawed off. Further, the two bolts connecting the midpipe to the asymmetric bracket also sheered right off. So there's a fair amount of rust on this car, just to give you an idea of how bad the situtation might be at the headers as well. __________________ 2011 E92 M3 mods: Alex tune, mod'd X-pipe, MPEv2, MS intake stage 2, ESS power pulley, Monoball bearings, SSFBs, PFv3 rotors, MFactory DSv3, RE SSK, Voltphreaks Li batt. For sale: E92M3: BW Race muffler, front thrust arms, stock muffler, 19" Vorsteiner VFF103 rims Z4MC: KW V3 coilovers (rears)
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10-09-2016, 09:50 PM	#2
FMLYSDN Major 1182 Rep 1,485 Posts Drives: 2011 Frozen Grey E90 M3 Join Date: Mar 2013 Location: Edmonton iTrader: (1) Garage List 2011 BMW E90 M3 Ind ... [10.00]	Perhaps a torch. Heat it up. Try banging it then? __________________ MODE CARBON \| BLOG \| FROZEN GREY E90 M3
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10-09-2016, 10:17 PM	#3
pbonsalb Lieutenant General 5234 Rep 10,616 Posts Drives: 18 F90 M5, 99 E36 M3 Turbo Join Date: Feb 2011 Location: New England iTrader: (4)	Support the front end of the pipes near the headers. Go to the rear of the midpipe, wiggle a few inches side to side while pulling.
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10-11-2016, 07:49 AM	#4
cmichaelo Second Lieutenant 46 Rep 221 Posts Drives: '10 E92 M3, '22 Toyota Rav4 Join Date: Oct 2009 Location: Peekskill, New York iTrader: (0)	I got it off. Overnight PB blaster broke loose rigth side. A little more gentle banging on left side and some wiggling of the pipes from the rear got the left side loose. Thanks for your advice. __________________ 2011 E92 M3 mods: Alex tune, mod'd X-pipe, MPEv2, MS intake stage 2, ESS power pulley, Monoball bearings, SSFBs, PFv3 rotors, MFactory DSv3, RE SSK, Voltphreaks Li batt. For sale: E92M3: BW Race muffler, front thrust arms, stock muffler, 19" Vorsteiner VFF103 rims Z4MC: KW V3 coilovers (rears)
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