Downpipe bolts rusting

Shieldze1025 · 11-02-2010, 09:12 AM

Hey guys,

I am installing my catback exhaust this weekend. I have heard from 2 friends that the downpipe bolts can be a problem, that they can rust and may need to be replaced.

Anyone have any input on this? Will some WD40 or something suffice as enough to remove and reuse the downpipe bolts? OR will the be so rusted that I will need new ones?

TIA.

-Shields

EDIT: I tried searching but only found people asking about using new DP's since the bolts are attached to the stock DP's. I will be using the stock ones still.

Kevin@AKMotorwerk · 11-02-2010, 09:13 AM

Quote:

Originally Posted by Shieldze1025

Hey guys,

I am installing my catback exhaust this weekend. I have heard from 2 friends that the downpipe bolts can be a problem, that they can rust and may need to be replaced.

Anyone have any input on this? Will some WD40 or something suffice as enough to remove and reuse the downpipe bolts? OR will the be so rusted that I will need new ones?

TIA.

-Shields

the stock dp's are studs, they break pretty easy, i would try to heat them if possible, or start spraying them with pb blaster every day until you do the exhaust, if they break, the studs will have to be drilled, or punched out of the dp.

bimmertt · 11-02-2010, 11:18 AM

PB blaster is a must. I've attempted exhaust installs before and they never turned out good because of rusted bolts snapping in half. It is easier if you have access to a lift and the proper tools.

And you will want new studs.

Shieldze1025 · 11-02-2010, 11:32 AM

OK cool thanks guy. Yea I was definitely gonna PBblast 'em and hope for the best. Im trying to figure out my best options for finding a lift or jacking the car up. My biggest problem right now is what to do with the stock exhaust when I get it off. I have no way of moving it to somewhere I can leave it haha.

Shieldze1025 · 11-02-2010, 11:33 AM

Quote:

Originally Posted by bimmertt

And you will want new studs.

Any idea where to get these?

vasillalov · 11-02-2010, 12:34 PM

Also, I recommend coating the bolts with some anti seize paste. It will prevent rusting.

scheherazade · 11-02-2010, 12:56 PM

I personally would get stainless bolts, then after installing, spray paint over the threads with 2000f paint.

DPs get silly hot, and a lot of typical anti-rust measures aren't an option.

-scheherazade

Shieldze1025 · 11-02-2010, 01:24 PM

Thanks guys

ar design · 11-02-2010, 02:48 PM

Quote:

Originally Posted by scheherazade

I personally would get stainless bolts, then after installing, spray paint over the threads with 2000f paint.

DPs get silly hot, and a lot of typical anti-rust measures aren't an option.

-scheherazade

Thing is, stainless bolts usually have much lower tensile strength. Our bolt kits have a special type of zinc coating that is VERY durable, AND the bolts are class 10.9.....

ar

vasillalov · 11-02-2010, 02:55 PM

Quote:

Originally Posted by ar design

, AND the bolts are class 10.9.....

ar

No offense, but what the hell does that mean? Just trying to understand, that's all...

Kevin@AKMotorwerk · 11-02-2010, 03:05 PM

Quote:

Originally Posted by vasillalov

No offense, but what the hell does that mean? Just trying to understand, that's all...

its the strength rating of the bolt, like a strong standard size bolt would be grade 8, well metric bolts are classed too, and that 10.9 is strong on the rating scale

vasillalov · 11-02-2010, 03:21 PM

Thanks Kevin! I appreciate it.

ar design · 11-02-2010, 05:03 PM

Quote:

Originally Posted by Kevin@AKMotorwerk

its the strength rating of the bolt, like a strong standard size bolt would be grade 8, well metric bolts are classed too, and that 10.9 is strong on the rating scale

NiVeDh · 11-06-2010, 09:09 PM

One of the studs on my stock DPs broke. What's the best way to get it out? I'll be replacing them with AR catless DPs soon but in the meantime, is it OK that I'm running my catback exhaust attached by using just one bolt for that midpipe? It is leaking slightly.

BrianMN · 11-06-2010, 10:01 PM

Pound it out is essentially the way to get it out...but be careful to not pound too hard with it attached to the turbo. Perhaps use some type of small puller or thredpress?

mycoupe · 11-06-2010, 10:19 PM

pull the dp off and use a press dude.

NiVeDh · 11-06-2010, 10:26 PM

Quote:

Originally Posted by BrianMN

Pound it out is essentially the way to get it out...but be careful to not pound too hard with it attached to the turbo. Perhaps use some type of small puller or thredpress?

Quote:

Originally Posted by mycoupe

pull the dp off and use a press dude.

Thanks guys. I'll be taking the DPs off within a couple of weeks but in the meantime, the one bolt should hold right? The leak doesn't bother me that much.

After it is pressed out, can regular bolts be used in its place in case I decide to go back to the stock DPs?

mycoupe · 11-06-2010, 10:30 PM

Quote:

Originally Posted by NiVeDh

Thanks guys. I'll be taking the DPs off within a couple of weeks but in the meantime, the one bolt should hold right? The leak doesn't bother me that much.

After it is pressed out, can regular bolts be used in its place in case I decide to go back to the stock DPs?

Can't comment on the bolts, but I would be super careful about the exhaust leak man. I had one in an integra I had years ago and it caused me to fall asleep at the wheel! Thankfully, I woke up as I hit the rumble strip and didn't lose control as I went off into the grassy median OR HIT SOMEONE ELSE!!!

NiVeDh · 11-06-2010, 11:00 PM

Quote:

Originally Posted by mycoupe

Can't comment on the bolts, but I would be super careful about the exhaust leak man. I had one in an integra I had years ago and it caused me to fall asleep at the wheel! Thankfully, I woke up as I hit the rumble strip and didn't lose control as I went off into the grassy median OR HIT SOMEONE ELSE!!!

Good call! I'm scared now. I will try to avoid driving as much as possible until I get the AR DPs installed.

BrianMN · 11-06-2010, 11:15 PM

Regular bolts are normal for aftermarket DP/Exhaust installs, and you'll be fine with 1 bolt for a couple weeks, just be aware of it and maybe roll the windows down when at a stop or something.

mycoupe · 11-07-2010, 12:13 AM

Quote:

Originally Posted by NiVeDh

Good call! I'm scared now. I will try to avoid driving as much as possible until I get the AR DPs installed.

Just lookin' out for you man! Hate to see someone else do what I did!

11-02-2010, 09:12 AM	#1
Shieldze1025 Keepin' America Free 72 Rep 1,260 Posts Drives: F10 535i Join Date: Dec 2009 Location: Haleiwa, HI iTrader: (7)	Downpipe bolts rusting - problem? Hey guys, I am installing my catback exhaust this weekend. I have heard from 2 friends that the downpipe bolts can be a problem, that they can rust and may need to be replaced. Anyone have any input on this? Will some WD40 or something suffice as enough to remove and reuse the downpipe bolts? OR will the be so rusted that I will need new ones? TIA. -Shields EDIT: I tried searching but only found people asking about using new DP's since the bolts are attached to the stock DP's. I will be using the stock ones still. __________________ F10 535i \| Retired: E60 ///M5 \| E92 335i "If everything seems under control, you're not going fast enough" -Mario Andretti
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11-02-2010, 11:18 AM	#3
bimmertt Lieutenant Colonel 93 Rep 1,794 Posts Drives: 2007 e92 335i Join Date: Nov 2008 Location: Earth iTrader: (7)	PB blaster is a must. I've attempted exhaust installs before and they never turned out good because of rusted bolts snapping in half. It is easier if you have access to a lift and the proper tools. And you will want new studs.
	Appreciate 0 Quote

11-02-2010, 11:32 AM	#4
Shieldze1025 Keepin' America Free 72 Rep 1,260 Posts Drives: F10 535i Join Date: Dec 2009 Location: Haleiwa, HI iTrader: (7)	OK cool thanks guy. Yea I was definitely gonna PBblast 'em and hope for the best. Im trying to figure out my best options for finding a lift or jacking the car up. My biggest problem right now is what to do with the stock exhaust when I get it off. I have no way of moving it to somewhere I can leave it haha. __________________ F10 535i \| Retired: E60 ///M5 \| E92 335i "If everything seems under control, you're not going fast enough" -Mario Andretti
	Appreciate 0 Quote

11-02-2010, 12:34 PM	#6
vasillalov Mad Linux Guru On The Loose 1121 Rep 5,396 Posts Drives: 2008 335i Sedan, 2023 M3 Join Date: Aug 2009 Location: Chicago, IL iTrader: (5) Garage List 2023 BMW M3 [0.00] 2008 335i E90 [8.00]	Also, I recommend coating the bolts with some anti seize paste. It will prevent rusting. __________________ 6MT \| COBB \| AR \| AE \| Forge DV \| HPF \| P3 Gauge \| Hybrid Intake \| O.S.Giken TCD \| All M3 bits \| TCKLine \| StopTech \| UUC \| ER \| SPEC
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11-02-2010, 12:56 PM	#7
scheherazade Major 36 Rep 1,467 Posts Drives: 09 GTR (& 93' accord!) Join Date: Sep 2008 Location: DC metro area iTrader: (8)	I personally would get stainless bolts, then after installing, spray paint over the threads with 2000f paint. DPs get silly hot, and a lot of typical anti-rust measures aren't an option. -scheherazade
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11-02-2010, 01:24 PM	#8
Shieldze1025 Keepin' America Free 72 Rep 1,260 Posts Drives: F10 535i Join Date: Dec 2009 Location: Haleiwa, HI iTrader: (7)	Thanks guys __________________ F10 535i \| Retired: E60 ///M5 \| E92 335i "If everything seems under control, you're not going fast enough" -Mario Andretti
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11-02-2010, 03:21 PM	#12
vasillalov Mad Linux Guru On The Loose 1121 Rep 5,396 Posts Drives: 2008 335i Sedan, 2023 M3 Join Date: Aug 2009 Location: Chicago, IL iTrader: (5) Garage List 2023 BMW M3 [0.00] 2008 335i E90 [8.00]	Thanks Kevin! I appreciate it. __________________ 6MT \| COBB \| AR \| AE \| Forge DV \| HPF \| P3 Gauge \| Hybrid Intake \| O.S.Giken TCD \| All M3 bits \| TCKLine \| StopTech \| UUC \| ER \| SPEC
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11-06-2010, 09:09 PM	#14
NiVeDh Major General 422 Rep 8,003 Posts Drives: '08 E90 335i, '99 E36 M3 Join Date: Apr 2009 Location: Houston, TX & Atlanta, GA iTrader: (132) Garage List 2008 BMW 335i Sedan [8.66]	One of the studs on my stock DPs broke. What's the best way to get it out? I'll be replacing them with AR catless DPs soon but in the meantime, is it OK that I'm running my catback exhaust attached by using just one bolt for that midpipe? It is leaking slightly.
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11-06-2010, 10:01 PM	#15
BrianMN Banned 114 Rep 2,428 Posts Drives: 4 Door Family Sedan Join Date: Sep 2009 Location: Minneapolis iTrader: (7)	Pound it out is essentially the way to get it out...but be careful to not pound too hard with it attached to the turbo. Perhaps use some type of small puller or thredpress?
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11-06-2010, 10:19 PM	#16
mycoupe Banned 55 Rep 1,495 Posts Drives: 07 335i coupe 6spd Join Date: Dec 2009 Location: cincinnati, Ohio iTrader: (5)	pull the dp off and use a press dude.
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11-06-2010, 11:15 PM	#20
BrianMN Banned 114 Rep 2,428 Posts Drives: 4 Door Family Sedan Join Date: Sep 2009 Location: Minneapolis iTrader: (7)	Regular bolts are normal for aftermarket DP/Exhaust installs, and you'll be fine with 1 bolt for a couple weeks, just be aware of it and maybe roll the windows down when at a stop or something.
	Appreciate 0 Quote