Exhaust Rattling on startup?...

BimmerBlack11 · 09-16-2009, 04:27 AM

it might be normal but i just wanted another opinion every time i start up my car it kinda has this rattling sound but at the same time it sounds like a chain or something... anyone know what it could be or if it's normal?

Thanks

enrita · 09-16-2009, 04:36 AM

got exactly the same , only cold motor at startup

TreDirtyFive · 09-16-2009, 05:15 AM

This is on a sock exhaust or?

Bomis · 09-16-2009, 06:32 AM

is it just when the car is cold? if not it might be some problems with the catalytic converters...

m3kerry · 09-16-2009, 06:43 AM

Most dual exhaust systems on bmw's have a vacuum tube that opens and closes one side of the exhaust until the o2 sensors heat up. My e46 330's came off for more than a year. After putting it back on there is some noise while it opens or closes in the morning.

You may want to get a light and look under the car.

WCM3 · 09-16-2009, 08:28 AM

Wastegate rattle?

ren · 09-16-2009, 08:36 AM

I think I have the same noise. I also had wastegate rattle and got a new set of turbos but this noise didn't go away. I will try to record it so we can compare but mine happens right before the exhaust flap closes and it doesn't matter if the engine is cold or not.

RedGT3 · 09-16-2009, 09:32 AM

Quote:

Originally Posted by WCM3

Wastegate rattle?

BINGO.

blisstik · 09-16-2009, 09:55 AM

Try the golf tee mod and if that doesn't make the noise go away, it could be the wastegate rattle. But typically, you can hear those on deceleration.

jpsimon · 09-16-2009, 10:28 AM

I had an issue like this at one point, i got under the car and one of the brackets that you screw in which supports the exhaust had come loose and was dangling parallel to them inbetween. Every other time I started the car or was at idle it sounded like a chain in a tin can.

long story short, that bolt was so rusted (thanks VT salt) that when i tried to loosen it it broke right in half.

David1 · 09-16-2009, 01:49 PM

The flap in the rear rattles on every BMW I have had. It occures a second or two after a cold start.

Bagelfast · 09-16-2009, 02:05 PM

Take a video and post it up, but usually its the wastegates rattling.

Mr. 5 · 09-16-2009, 02:46 PM

Quote:

Originally Posted by WCM3

Wastegate rattle?

Yep.
It's the wastegates closing during start up.
It's normal.

WCM3 · 09-16-2009, 02:57 PM

Quote:

Originally Posted by Mr. 5

It's normal.

Which is very, very sad..

BimmerBlack11 · 09-16-2009, 03:16 PM

thanks for the replies guys, yeah it seems to just do it on a cold start and the only mods i got is the dual cone ex. probably gonna get the quad ex. later on, but yeah i guess it's normal n i never ask the dealership it always seems like they got something to say haha...

CubanJJ09 · 09-16-2009, 04:17 PM

i had a problem with the bracket, they grinded it down a little for me cause it was hitting the metal head shield thats on top of the muffler

09-16-2009, 04:27 AM	#1
BimmerBlack11 New Member 3 Rep 29 Posts Drives: 11 M 335i SP Join Date: Aug 2009 Location: Washington iTrader: (2)	Exhaust Rattling on startup?... it might be normal but i just wanted another opinion every time i start up my car it kinda has this rattling sound but at the same time it sounds like a chain or something... anyone know what it could be or if it's normal? Thanks
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09-16-2009, 04:36 AM	#2
enrita Major General 161 Rep 7,378 Posts Drives: 335i - Big turbos Join Date: Sep 2008 Location: Italian in Sweden iTrader: (0)	got exactly the same , only cold motor at startup __________________ 07 335i AT - MOTIV 750 - MHD E85 BMS flash - BMS PI - JB4G5 - Okada Coils - NGK 5992 Plugs - Helix IC - Snow Stg. 3 - Stett CP - Custom midpipes with 100 HJS Cats - Bastuck Quad - PSS10 - QUAIFE LSD - BMS OCC - Forge DVs - AR OC - ALCON BBK - M3 Chassi - Dinan CP - Velocity M rear Toe arms - Advan RZ-DF - LUX H8 - Level 10 AT upgrade
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09-16-2009, 05:15 AM	#3
TreDirtyFive Major 253 Rep 1,334 Posts Drives: X3 M40i Join Date: Jun 2008 Location: Los Angeles, CA iTrader: (11)	This is on a sock exhaust or? __________________ X3 M40i G01, M235i F22, 335 F30 MSport, 135 DCT, 335 E92, Audi A3
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09-16-2009, 06:32 AM	#4
Bomis Captain 63 Rep 989 Posts Drives: BMW E92 M3 Join Date: Apr 2009 Location: Sweden iTrader: (1)	is it just when the car is cold? if not it might be some problems with the catalytic converters... __________________ EURO E92 M3 2008 6MT Interlagos ///*Fully Loaded!* Evolve-R ECU Flash/Gintani Sport Exhaust/MS Stg2 Intake Kit/H&R Springs/MS 18/15 mm spacers/Bmw Perf. Grills/Gloss Black side gills/LCI Tails/LUX V3's/RD license plate leds
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09-16-2009, 06:43 AM	#5
m3kerry SCCA B Street 117 Rep 660 Posts Drives: 1 M Join Date: Mar 2009 Location: Dallas iTrader: (0)	Most dual exhaust systems on bmw's have a vacuum tube that opens and closes one side of the exhaust until the o2 sensors heat up. My e46 330's came off for more than a year. After putting it back on there is some noise while it opens or closes in the morning. You may want to get a light and look under the car. __________________ www.facebook.com/thatsrightracing
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09-16-2009, 08:28 AM	#6
WCM3 Î canŧ főcus mŷ attėntĭon 72 Rep 1,406 Posts Drives: 13 Rubicon Join Date: May 2008 Location: Morgantown, Pa iTrader: (7)	Wastegate rattle? __________________ 2011 M3 Coupe - Individual Fire Orange/Black Novillo Extended Leather, 6MT, Mode Carbon, Eisenmann Race, BBS CH-R, BC Coil-overs (Sold) 1995 M3 Coupe - Avus/Hurricane, AEM EMS, Precision Turbo, Boostlogic, H&R, Fikse FM/5, MaxVelocity, Maximum PSI, 20% Tint, etc etc..(Sold) 2009 M3 Coupe - AW/Fox Red, 6MT, Carbon Roof, Shadow Trim, etc (Sold)
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09-16-2009, 08:36 AM	#7
ren Captain 60 Rep 839 Posts Drives: 2024 X7 M60i Join Date: Jan 2007 Location: U.S. iTrader: (8)	I think I have the same noise. I also had wastegate rattle and got a new set of turbos but this noise didn't go away. I will try to record it so we can compare but mine happens right before the exhaust flap closes and it doesn't matter if the engine is cold or not.
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09-16-2009, 09:55 AM	#9
blisstik Lieutenant Colonel 151 Rep 1,677 Posts Drives: E92 Join Date: Jul 2009 Location: California iTrader: (14)	Try the golf tee mod and if that doesn't make the noise go away, it could be the wastegate rattle. But typically, you can hear those on deceleration.
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09-16-2009, 10:28 AM	#10
jpsimon Team Zissou 3065 Rep 10,197 Posts Drives: 2022 AWD M3 Comp - SMB Join Date: Dec 2006 Location: CT iTrader: (7)	I had an issue like this at one point, i got under the car and one of the brackets that you screw in which supports the exhaust had come loose and was dangling parallel to them inbetween. Every other time I started the car or was at idle it sounded like a chain in a tin can. long story short, that bolt was so rusted (thanks VT salt) that when i tried to loosen it it broke right in half. Last edited by jpsimon; 09-16-2009 at 01:57 PM..
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09-16-2009, 01:49 PM	#11
David1 Brigadier General 814 Rep 3,949 Posts Drives: 09 E92 09 X5 Join Date: Mar 2007 Location: Columbus, OH iTrader: (1)	The flap in the rear rattles on every BMW I have had. It occures a second or two after a cold start. __________________ 2021 M2 Comp Sunset Orange \|Black with orange Stitching Dakota Leather\|Executive Pkg\|DCT
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09-16-2009, 02:05 PM	#12
Bagelfast Lieutenant Colonel 125 Rep 1,546 Posts Drives: BMW Join Date: Sep 2008 Location: USA iTrader: (0)	Take a video and post it up, but usually its the wastegates rattling.
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09-16-2009, 03:16 PM	#15
BimmerBlack11 New Member 3 Rep 29 Posts Drives: 11 M 335i SP Join Date: Aug 2009 Location: Washington iTrader: (2)	. thanks for the replies guys, yeah it seems to just do it on a cold start and the only mods i got is the dual cone ex. probably gonna get the quad ex. later on, but yeah i guess it's normal n i never ask the dealership it always seems like they got something to say haha...
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09-16-2009, 04:17 PM	#16
CubanJJ09 Banned 169 Rep 12,680 Posts Drives: like an asshole Join Date: Feb 2008 Location: Chicago Burbs iTrader: (2) Garage List 2007 BMW 335i [6.18]	i had a problem with the bracket, they grinded it down a little for me cause it was hitting the metal head shield thats on top of the muffler
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