Need Help! Downpipe-midpipe studs broke; misfires; hiccups/stutting...Suggestions?

Lshaw · 01-03-2013, 10:43 PM

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DallasBoosted · 01-03-2013, 10:50 PM

It probably just needs new plugs/coils. Most misfires are due to this. If it's persistent cylinder 5 I'd replace all the plugs first (likely can get this done as part of your 30k service), if you keep getting a cylinder 5 misfire, get the code stored and then de-mod it and take it in and let them replace the coil.

On the other hand, the coils are only 40 bucks.

kfrazie1 · 01-05-2013, 12:22 PM

I did the same thing to my down pipes. Realized those studs are welded to the down pipes and can't be removed. Landed up cutting them flush and drilling them out. Put in some nice ss bolts with anti seize.

Fully_Bolted · 01-05-2013, 01:07 PM

Quote:

Originally Posted by kfrazie1

I did the same thing to my down pipes. Realized those studs are welded to the down pipes and can't be removed. Landed up cutting them flush and drilling them out. Put in some nice ss bolts with anti seize.

This. For misfires, start with a fresh set of plugs. If your still getting misfires swap coils to see if the misfire follows the coil and replace as necessary.

JohnSprm69 · 01-05-2013, 01:21 PM

Quote:

Originally Posted by l3n1356

While removing the stock exhaust one stud/bolt on each of the pipes broke

Quote:

Originally Posted by kfrazie1

I did the same thing to my down pipes. Realized those studs are welded to the down pipes and can't be removed. Landed up cutting them flush and drilling them out. Put in some nice ss bolts with anti seize.

how did you guys manage to break those bolts? or they broke by themselves when taking the nuts out?

op: i would look into buying used stock dp or take advantage and buy aftermarket dp

good luck

Lshaw · 01-08-2013, 10:14 AM

Quote:

Originally Posted by DallasBoosted

It probably just needs new plugs/coils. Most misfires are due to this. If it's persistent cylinder 5 I'd replace all the plugs first (likely can get this done as part of your 30k service), if you keep getting a cylinder 5 misfire, get the code stored and then de-mod it and take it in and let them replace the coil.

On the other hand, the coils are only 40 bucks.

Thanks for the advice. I plan on getting all spark plugs replaced and what not, I have no clue how the previous owner drove the car. Compared to my previous 335xi, my car now runs like shit. Ill probably get a walnut blast as well.

But... What is every ones thought about leaving the dp bolts unfixed before my 30k service? I currently have no tools or lift currently.

Lshaw · 01-08-2013, 10:16 AM

Quote:

Originally Posted by Swoosh69

Quote:

Originally Posted by l3n1356

While removing the stock exhaust one stud/bolt on each of the pipes broke

Quote:

Originally Posted by kfrazie1

I did the same thing to my down pipes. Realized those studs are welded to the down pipes and can't be removed. Landed up cutting them flush and drilling them out. Put in some nice ss bolts with anti seize.

how did you guys manage to break those bolts? or they broke by themselves when taking the nuts out?

op: i would look into buying used stock dp or take advantage and buy aftermarket dp

good luck

They were seized

and I guess while trying to untorque them, the stud twisted off...

BoostAddict · 01-08-2013, 10:52 PM

If you didn't get those out already, take a cutting wheel and cut the flange parallel to the stud to release the tension. Then take a screw driver and hammer and it should come out pretty easy. M8 bolts fit in perfectly. This is a pretty common occurrence.

Lshaw · 01-09-2013, 10:03 AM

Quote:

Originally Posted by ***********

If you didn't get those out already, take a cutting wheel and cut the flange parallel to the stud to release the tension. Then take a screw driver and hammer and it should come out pretty easy. M8 bolts fit in perfectly. This is a pretty common occurrence.

Ive done that already, with heat applied as well. I dont want to hammer to hard bc of the turbo. Ive also tried an air gun. Im just going to have a shop drill it out.

Lshaw · 01-15-2013, 04:19 PM

Does anyone know the stud part #? Or a replacement? I want something comparable to oem so they wont give me any problems for using other than oem bolts and nuts.

Tiago@VRSF · 01-15-2013, 08:46 PM

There's no replacement part number for that stud. I recommend using grade 12 nuts and bolts to replace them. That'll keep you out of trouble in the future.

kfrazie1 · 01-15-2013, 09:04 PM

Quote:

Originally Posted by l3n1356

They were seized

and I guess while trying to untorque them, the stud twisted off...

Yes, the nut was seized. Landed up stripping the nut. I decided to grind the nut off and try to heat the stud up with a torch and punch it out. Then I realized it was welded - fml.

Tiago@VRSF · 01-15-2013, 09:14 PM

You can punch them out, I've had to before.

01-03-2013, 10:43 PM	#1
Lshaw Lieutenant Colonel 251 Rep 1,869 Posts Drives: 09 335i 6mt Join Date: Oct 2007 Location: NYC/Pittsburgh iTrader: (21)	close close Last edited by Lshaw; 06-13-2019 at 12:24 PM..
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01-03-2013, 10:50 PM	#2
DallasBoosted Captain 38 Rep 864 Posts Drives: '08 E92 335i Join Date: Apr 2012 Location: Dallas iTrader: (3) Garage List 2008 BMW 335i [10.00]	It probably just needs new plugs/coils. Most misfires are due to this. If it's persistent cylinder 5 I'd replace all the plugs first (likely can get this done as part of your 30k service), if you keep getting a cylinder 5 misfire, get the code stored and then de-mod it and take it in and let them replace the coil. On the other hand, the coils are only 40 bucks.
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01-05-2013, 12:22 PM	#3
kfrazie1 Lieutenant 64 Rep 553 Posts Drives: 335i Join Date: Aug 2010 Location: NY iTrader: (4)	I did the same thing to my down pipes. Realized those studs are welded to the down pipes and can't be removed. Landed up cutting them flush and drilling them out. Put in some nice ss bolts with anti seize. __________________ Montego Blue E90 335i 7" VRSF IC \| OFT Tune \| DCI \| RB PCV \| Secondary CAT Delete & CYBA 3.75" Tips \| M3 Front \| Mtech Rear \| CSL Trunk \| 219M \| KW V1 \| AA CP
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01-08-2013, 10:52 PM	#8
BoostAddict Banned 48 Rep 932 Posts Drives: SGM 335i Join Date: Jan 2010 Location: Boynton Beach, FL iTrader: (4)	If you didn't get those out already, take a cutting wheel and cut the flange parallel to the stud to release the tension. Then take a screw driver and hammer and it should come out pretty easy. M8 bolts fit in perfectly. This is a pretty common occurrence.
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01-15-2013, 04:19 PM	#10
Lshaw Lieutenant Colonel 251 Rep 1,869 Posts Drives: 09 335i 6mt Join Date: Oct 2007 Location: NYC/Pittsburgh iTrader: (21)	Does anyone know the stud part #? Or a replacement? I want something comparable to oem so they wont give me any problems for using other than oem bolts and nuts.
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01-15-2013, 08:46 PM	#11
Tiago@VRSF 2095 Rep 43,350 Posts Drives: F90 M5 Join Date: Dec 2007 Location: Doral, FL iTrader: (99) Garage List 2014 F30 328xi [0.00] 2015 F82 BMW M4 [0.00] 2013 Ducati 1199 Pa ... [0.00] 2008 BMW 335i [0.00]	There's no replacement part number for that stud. I recommend using grade 12 nuts and bolts to replace them. That'll keep you out of trouble in the future.
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01-15-2013, 09:14 PM	#13
Tiago@VRSF 2095 Rep 43,350 Posts Drives: F90 M5 Join Date: Dec 2007 Location: Doral, FL iTrader: (99) Garage List 2014 F30 328xi [0.00] 2015 F82 BMW M4 [0.00] 2013 Ducati 1199 Pa ... [0.00] 2008 BMW 335i [0.00]	You can punch them out, I've had to before.
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