metallic rattle on startup-then goes away (exhaust)

Twhill19 · 10-02-2013, 06:47 AM

Featured on BIMMERPOST.com

i have this kinda low frequency metallic rattle on cold starts only that seems to subside as soon as the engine revs drop to normal idle...

i tried taking a sound clip/video of it but it doesn't really come out that well so it would be useless to post...the exhaust completely drowns it out (straight pipes/catless, yaddah)

17,000 miles on the car...Berk axle back/berk mids/AR DP...never had any issues aside from midpipe knock on subframe...could this be it? rocks in exhaust? wastegate? loose bolts? (had them checked 2k miles ago) faulty hangar?

help!

jbertino · 10-02-2013, 07:20 AM

Quote:

Originally Posted by Twhill19

i have this kinda low frequency metallic rattle on cold starts only that seems to subside as soon as the engine revs drop to normal idle...

i tried taking a sound clip/video of it but it doesn't really come out that well so it would be useless to post...the exhaust completely drowns it out (straight pipes/catless, yaddah)

17,000 miles on the car...Berk axle back/berk mids/AR DP...never had any issues aside from midpipe knock on subframe...could this be it? rocks in exhaust? wastegate? loose bolts? (had them checked 2k miles ago) faulty hangar?

help!

Ive had the same thing for the last month . I think it is just waste gate rattling

BrewRifle · 10-02-2013, 08:25 AM

Most likely waste gate rattle. Mine does it as well.

RimasRS · 10-02-2013, 09:50 AM

My guess could be dual mass flywheel

marc@x-ph.com · 10-02-2013, 09:53 AM

I would have said that it could be your exhaust flap, but then you have an upgraded exhaust.

so yeah It's most probably your wastegates.

To be sure, try to recreate the noise after startup. slight tap on the throttle or may be rev to 3k, let the throttle go and wait for it.

Twhill19 · 10-02-2013, 09:56 AM

Quote:

Originally Posted by marc@x-ph.com

I would have said that it could be your exhaust flap, but then you have an upgraded exhaust.

so yeah It's most probably your wastegates.

To be sure, try to recreate the noise after startup. slight tap on the throttle or may be rev to 3k, let the throttle go and wait for it.

Happens every cold start but to be honest the exhaust is so loud from 2.5k rpms I can't tell haha

Miko226 · 10-02-2013, 10:59 AM

I have the same as well it is Waste gate rattling might be getting close to the time to swap them out if it gets worse

jbertino · 10-02-2013, 11:05 AM

Quote:

Originally Posted by Miko226

I have the same as well it is Waste gate rattling might be getting close to the time to swap them out if it gets worse

Mine just started doing it. But my rattle isn't really noticeable whole driving

Miko226 · 10-02-2013, 12:49 PM

Quote:

Originally Posted by jbertino

Mine just started doing it. But my rattle isn't really noticeable whole driving

Yeah same here not very noticeable if at all while driving

e34m5 · 10-02-2013, 01:02 PM

Almost guaranty it is Waste Gate rattle. While stopped, rev engine and quickly release throttle. You will always hear rattle as RPM's decrease and excess pressure is released.

There is post in the E90 that shows how to adjust the rods in the WG to eliminte rattle. Hard to access, but doable.

Twhill19 · 10-02-2013, 04:48 PM

Quote:

Originally Posted by e34m5

Almost guaranty it is Waste Gate rattle. While stopped, rev engine and quickly release throttle. You will always hear rattle as RPM's decrease and excess pressure is released.

There is post in the E90 that shows how to adjust the rods in the WG to eliminte rattle. Hard to access, but doable.

Thanks guys cars going in Monday to get checked out I'm not mechanically gifted enough to mess with myself I'll make it worse haha

Twhill19 · 10-02-2013, 04:49 PM

17k is a little soon no?

Twhill19 · 10-03-2013, 12:57 AM

100% wastes. Played with the throttle a lot in my garage in gear/neutral etc...sounds like quiet metallic fluttering...increases with rpm's...decreases as they fall. Doesn't 17,500 miles seem a little early for wastegates??

RimasRS · 10-03-2013, 02:40 AM

Quote:

Originally Posted by Twhill19

100% wastes. Played with the throttle a lot in my garage in gear/neutral etc...sounds like quiet metallic fluttering...increases with rpm's...decreases as they fall. Doesn't 17,500 miles seem a little early for wastegates??

Disconnect vacuum lines from two vacuum tanks and see if you still here it... You will discover that it is not wastegates...

Twhill19 · 10-03-2013, 02:48 AM

Quote:

Originally Posted by RimasRS

Quote:

Originally Posted by Twhill19

100% wastes. Played with the throttle a lot in my garage in gear/neutral etc...sounds like quiet metallic fluttering...increases with rpm's...decreases as they fall. Doesn't 17,500 miles seem a little early for wastegates??

Disconnect vacuum lines from two vacuum tanks and see if you still here it... You will discover that it is not wastegates...

I'm clueless on wastes what do you think it is?

Twhill19 · 10-03-2013, 02:49 AM

Quote:

Originally Posted by RimasRS

Quote:

Originally Posted by Twhill19

100% wastes. Played with the throttle a lot in my garage in gear/neutral etc...sounds like quiet metallic fluttering...increases with rpm's...decreases as they fall. Doesn't 17,500 miles seem a little early for wastegates??

Disconnect vacuum lines from two vacuum tanks and see if you still here it... You will discover that it is not wastegates...

Just loose vac lines?

sharkatron · 10-03-2013, 06:45 AM

Quote:

Originally Posted by Twhill19

Quote:

Originally Posted by RimasRS

Quote:

Originally Posted by Twhill19

100% wastes. Played with the throttle a lot in my garage in gear/neutral etc...sounds like quiet metallic fluttering...increases with rpm's...decreases as they fall. Doesn't 17,500 miles seem a little early for wastegates??

Disconnect vacuum lines from two vacuum tanks and see if you still here it... You will discover that it is not wastegates...

Just loose vac lines?

If you disconnect the vacuum lines and the sound disappears, most likely your wastegates. If there is no change, then most likely not your wastegates.

RimasRS · 10-03-2013, 07:14 AM

Quote:

Originally Posted by sharkatron

If you disconnect the vacuum lines and the sound disappears, most likely your wastegates. If there is no change, then most likely not your wastegates.

+1

lakylester · 10-04-2013, 08:06 PM

I agree with mostly everyone. I had the same issue. If you are decelerating in an enclosed space you can hear the rattle as well.

livnpaintball2 · 10-11-2013, 09:11 AM

He has a N55 not a N54.

10-02-2013, 06:47 AM	#1
Twhill19 hungry Drives: 2012-135i-N55 Join Date: May 2012 Location: Boston, MA Posts: 768 iTrader: (0)	metallic rattle on startup-then goes away (exhaust) Featured on BIMMERPOST.com i have this kinda low frequency metallic rattle on cold starts only that seems to subside as soon as the engine revs drop to normal idle... i tried taking a sound clip/video of it but it doesn't really come out that well so it would be useless to post...the exhaust completely drowns it out (straight pipes/catless, yaddah) 17,000 miles on the car...Berk axle back/berk mids/AR DP...never had any issues aside from midpipe knock on subframe...could this be it? rocks in exhaust? wastegate? loose bolts? (had them checked 2k miles ago) faulty hangar? help! __________________ 2012-135i-N55 - Dinan Stage 2. aFe Stage 2 CAI. Berk Mid-Pipes. Berk Race Axle-Back. AR Design Catless-DP. AA Charge-Pipe. ETS FMIC. 19" Forgestar F-14's 8.5"/9.0". Michelin Pilot SS (225/35/19+255/30/19). Amber Delete. AutoCarbon CF Trunk-Spoiler. BMW M Performance Rotors/Pads. 20% tints (Coming soon: Dinan Stage 3, Dinan Oil Cooler, Custom Quad Turbo-Back Exhaust).
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10-02-2013, 09:53 AM	#5
marc@x-ph.com Captain Drives: 2010 e92 335i Join Date: Sep 2013 Location: USA Posts: 626 iTrader: (0)	I would have said that it could be your exhaust flap, but then you have an upgraded exhaust. so yeah It's most probably your wastegates. To be sure, try to recreate the noise after startup. slight tap on the throttle or may be rev to 3k, let the throttle go and wait for it. __________________ End Of Year SaleLowest Price Guarantee Amazing Deals On VRSF and BMS Products*Insane Active Autowerke Combo PackagesSpecials on ER and ETS Products** Visit Our Website----> www.ExtremePowerHouse.com Like Our Facebook Page for exclusive offers ---->https://www.facebook.com/extremepowerhouse?ref=hl
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10-02-2013, 10:59 AM	#7
Miko226 Private First Class Drives: 08 135i Black Join Date: Nov 2012 Location: Boca Raton, FL Posts: 196 iTrader: (0)	I have the same as well it is Waste gate rattling might be getting close to the time to swap them out if it gets worse __________________ Black 08 n54 135i Alpina AT 70k Engine: JB4 e40/93, BMS Tstat, AFE DCI, VRSF FMIC 5"(On Deck) Exhaust: Active DP, n55 Mids (Next), Berk Ceramic Delete Exterior: Cree LED AE, Matte Kidney, Ambergone, Tint Front 50%/2%/0% Rear + Taillights Tires: Nitto 555 265/35, Nitto Invo 235/40
	0

10-02-2013, 04:49 PM	#12
Twhill19 hungry Drives: 2012-135i-N55 Join Date: May 2012 Location: Boston, MA Posts: 768 iTrader: (0)	17k is a little soon no? __________________ 2012-135i-N55 - Dinan Stage 2. aFe Stage 2 CAI. Berk Mid-Pipes. Berk Race Axle-Back. AR Design Catless-DP. AA Charge-Pipe. ETS FMIC. 19" Forgestar F-14's 8.5"/9.0". Michelin Pilot SS (225/35/19+255/30/19). Amber Delete. AutoCarbon CF Trunk-Spoiler. BMW M Performance Rotors/Pads. 20% tints (Coming soon: Dinan Stage 3, Dinan Oil Cooler, Custom Quad Turbo-Back Exhaust).
	0

10-03-2013, 12:57 AM	#13
Twhill19 hungry Drives: 2012-135i-N55 Join Date: May 2012 Location: Boston, MA Posts: 768 iTrader: (0)	100% wastes. Played with the throttle a lot in my garage in gear/neutral etc...sounds like quiet metallic fluttering...increases with rpm's...decreases as they fall. Doesn't 17,500 miles seem a little early for wastegates?? __________________ 2012-135i-N55 - Dinan Stage 2. aFe Stage 2 CAI. Berk Mid-Pipes. Berk Race Axle-Back. AR Design Catless-DP. AA Charge-Pipe. ETS FMIC. 19" Forgestar F-14's 8.5"/9.0". Michelin Pilot SS (225/35/19+255/30/19). Amber Delete. AutoCarbon CF Trunk-Spoiler. BMW M Performance Rotors/Pads. 20% tints (Coming soon: Dinan Stage 3, Dinan Oil Cooler, Custom Quad Turbo-Back Exhaust).
	0

10-02-2013, 08:25 AM	#3
BrewRifle Private Drives: 2011 Monte Carlo Blue E92 M3 Join Date: Jun 2013 Location: Austin, Texas Posts: 98 iTrader: (2)	Most likely waste gate rattle. Mine does it as well.
	0

10-02-2013, 09:50 AM	#4
RimasRS Colonel Drives: 135i MT 2009 AW Join Date: Sep 2010 Location: Europe Posts: 2,217 iTrader: (0)	My guess could be dual mass flywheel
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10-02-2013, 01:02 PM	#10
e34m5 Captain Drives: 135i Join Date: Jun 2007 Location: Atlanta Posts: 908 iTrader: (0)	Almost guaranty it is Waste Gate rattle. While stopped, rev engine and quickly release throttle. You will always hear rattle as RPM's decrease and excess pressure is released. There is post in the E90 that shows how to adjust the rods in the WG to eliminte rattle. Hard to access, but doable.
	0

10-04-2013, 08:06 PM	#19
lakylester Private First Class Drives: b5.5 passat Join Date: Sep 2011 Location: nj Posts: 102 iTrader: (0)	I agree with mostly everyone. I had the same issue. If you are decelerating in an enclosed space you can hear the rattle as well.
	0

10-11-2013, 09:11 AM	#20
livnpaintball2 Private Drives: E82 N54 Join Date: Mar 2013 Location: Dfw Posts: 89 iTrader: (0)	He has a N55 not a N54.
	0

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