Metallic ringing on startup with sportcat

Mosely · 10-31-2017, 06:15 PM

Just put on a fabspeed sport cat over the weekend. When I was under the car on the first startup after installing it, I noticed a metallic ring type of noise coming from the exhaust. I had never listened to the car from underneath with stock exhaust so I didn't know if it was normal or not so I left it as is. Now on cold starts there is a distinct metallic ring for the first 10-20 seconds that seems to go away after the valve closes. I can hear it from inside the car with the windows closed and it definitely wasn't there before. I think everything lined up nicely on the install and I used all new gaskets including the V Band Crush gasket for the midpipe. Any thoughts?

Orange fever · 11-01-2017, 12:53 AM

a vid will help us out to help you.

Mosely · 11-01-2017, 07:50 AM

I'll try taking one later today. It's pretty subtle, we'll see if it picks up over the sound of the exhaust itself

Reading more last night I think it's the wastegate that's open on startup making it so loud, not the valve. So may be related to that more so.

Mosely · 11-01-2017, 10:41 PM

Not the greatest audio but just for context, the audio picks up right after the initial loudest 8-10 seconds of the cold start (this was too loud for the mic), where it gets slightly quieter, and then at 15-16 seconds you can hear it go into normal idling. You can clearly hear the metallic ringing noise in this middle period. I assume the first 8-10 seconds of cold start is open wastegate and then that closes and the valve stays closed/open (?) for the next 5-10 seconds before it gets quiet. The metallic noise happens from initial startup to when the valve changes. It's not coming from the engine bay at all and appears to be loudest right at the downpipe/midpipe area but I can't really localize it. Any ideas?

Edit: this is a 2018 m2 with 1300 miles, no other mods.

Mosely · 11-12-2017, 06:25 PM

Any thoughts?

David1 · 11-12-2017, 07:40 PM

Reinstall it. Something is vibrating. Make sure the v-clamps ate seated correctly.

Mosely · 11-15-2017, 01:31 PM

Quote:

Originally Posted by David1

Reinstall it. Something is vibrating. Make sure the v-clamps ate seated correctly.

Reinstalled the whole thing, there are definitely no leaks and the vbands look perfect and there are no spots that are rubbing. The noise appears to be coming from the the crossmember that the midpipe attaches to or the transmission directly above that. It actually doesn't sound like it's coming from the exhaust. Still can only hear it on cold start while the wastegate and valve are open. Not sure why it's just started after install of the downpipe, maybe it's just the vibrations of the increased flow/sound...

NO_USER_ · 11-18-2017, 03:38 PM

Quote:

Originally Posted by BimBimma

Reinstalled the whole thing, there are definitely no leaks and the vbands look perfect and there are no spots that are rubbing. The noise appears to be coming from the the crossmember that the midpipe attaches to or the transmission directly above that. It actually doesn't sound like it's coming from the exhaust. Still can only hear it on cold start while the wastegate and valve are open. Not sure why it's just started after install of the downpipe, maybe it's just the vibrations of the increased flow/sound...

Could possibly be the exhaust valve vibrating...

I've had that happen on multiple aftermarket exhausts (sounds just like your video), usually when the valve is closed however. Do you have a valve controller for opening and closing?

Mosely · 12-14-2017, 08:18 AM

Update: the noise is getting louder. Still most prominent in a cold start but I can hear it through the engine noise while driving now. I'm considering taking off the downpipe to see if it changes or goes away. Not really sure what's causing it anymore

gtaM2 · 12-14-2017, 09:26 AM

could be anything but how about the end of the long bolt on the clamp? maybe it's hitting something like the metallic under panel?

AndrewC1989 · 12-14-2017, 09:51 AM

start the car while it's on a lift. that should help you find your problem area real quick.

Mosely · 12-14-2017, 12:35 PM

Quote:

Originally Posted by andrewc89

start the car while it's on a lift. that should help you find your problem area real quick.

I started the car while on jacks (and crawled under after). It's hard to say exactly where it's coming from but like I mentioned previously it seems to be above the cross member that the mid pipe attached to. I started with and without that bracket attached and the noise persisted. It almost sounds like it's in the back part of the transmission area but clutch in and out doesn't change the noise at all. I'm really not sure what to make of it or how a simple down pipe change could cause the change. I'd like to avoid taking it off again as it's a bitch to do but may end up at that point

Mosely · 12-14-2017, 12:36 PM

Quote:

Originally Posted by gtaM2

could be anything but how about the end of the long bolt on the clamp? maybe it's hitting something like the metallic under panel?

I've checked the clearance on everything and it appears solid. It's also loudest right after cold start which makes me thing it's exhaust flow related?

mike@x-ph.com · 12-14-2017, 04:22 PM

It wont go away on its own, did you check the exhaust valves?

Mosely · 12-14-2017, 06:03 PM

Quote:

Originally Posted by mike@x-ph.com

It wont go away on its own, did you check the exhaust valves?

Was contemplating unplugging them to see if it has any effect open or closed but with it happening in sport and comfort I would think the valves may not be implicated?

David1 · 12-14-2017, 06:53 PM

Quote:

Originally Posted by BimBimma

Quote:

Originally Posted by mike@x-ph.com

It wont go away on its own, did you check the exhaust valves?

Was contemplating unplugging them to see if it has any effect open or closed but with it happening in sport and comfort I would think the valves may not be implicated?

Did you swap the brass gasket from the oem pipe to the new one?

Daleb · 12-14-2017, 07:33 PM

Most likely the wastegate on the turbo, sports cat just amplifies it over the oem cat.

Mosely · 12-14-2017, 08:41 PM

Quote:

Originally Posted by David1

Did you swap the brass gasket from the oem pipe to the new one?

I bought a new gasket for the turbo side of the downpipe, reused the upper vband, and use a brand new brass crush vband for the midpipe side of things.

CantComplain · 12-14-2017, 09:02 PM

Quote:

Originally Posted by BimBimma

I bought a new gasket for the turbo side of the downpipe, reused the upper vband, and use a brand new brass crush vband for the midpipe side of things.

Have you reached out to FabSpeed or your vendor for support? I would expect they'd have a good idea and interest in addressing your issue.

Subscribing. I'm interested in exactly this setup and a little concerned.

Lukeni · 12-15-2017, 01:10 AM

Got this sound too with my 300cpsi catted HJS dp. Sounds normal to me. Might be the open wastegate during coldstart...?

ORIGIN M. · 12-15-2017, 01:27 AM

Hmmm good to know!

Quote:

Originally Posted by Lukeni

Got this sound too with my 300cpsi catted HJS dp. Sounds normal to me. Might be the open wastegate during coldstart...?

XProject · 12-15-2017, 03:30 AM

I also have that metallic ringing sound at cold start, but after the valve closed, it goes away. The shop installed it. Mine is not as bad as yours. Maybe because of your bad recording and garage parking lot. I didn't notice the metal ring until ~300 miles because my exhaust got a lot louder after awhile (in a good way) lol.

That ringing sound is only at the cold start (5-10s). I thought I'm the only one. I just feel sorry for my neighbor when I go to work. I wish I can fix it oh well...

10-31-2017, 06:15 PM	#1
Mosely Lieutenant 594 Rep 450 Posts Drives: '18 M2 \| '20 X5 \| '07 E92 Join Date: Mar 2017 Location: SoCal iTrader: (1)	Metallic ringing on startup with sportcat Just put on a fabspeed sport cat over the weekend. When I was under the car on the first startup after installing it, I noticed a metallic ring type of noise coming from the exhaust. I had never listened to the car from underneath with stock exhaust so I didn't know if it was normal or not so I left it as is. Now on cold starts there is a distinct metallic ring for the first 10-20 seconds that seems to go away after the valve closes. I can hear it from inside the car with the windows closed and it definitely wasn't there before. I think everything lined up nicely on the install and I used all new gaskets including the V Band Crush gasket for the midpipe. Any thoughts?
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11-01-2017, 12:53 AM	#2
Orange fever Colonel 2351 Rep 2,829 Posts Drives: E36M,E46M,E90M,X5M,i3,M2,i8 Join Date: Dec 2007 Location: SoCal. in the hood!!! iTrader: (5)	a vid will help us out to help you. __________________ BMW I12 i8 Frozen Yellow- H&R springs, 22" Radenergie F10 Monoblock Forged /// F87 M2 Aw -Vorsteiner Aero Kit, VFF-107,Macht Schnell-Springs,VF-Engineering/Hex tuning Stage Two,ER DP,Stock Exhaust,Drop-In Bmc Filter,AA Intercooler,FTP Charge pipe+boost pipe/// Wish list :Mexico delivery 2024 BMW M2 (G87)
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11-01-2017, 07:50 AM	#3
Mosely Lieutenant 594 Rep 450 Posts Drives: '18 M2 \| '20 X5 \| '07 E92 Join Date: Mar 2017 Location: SoCal iTrader: (1)	I'll try taking one later today. It's pretty subtle, we'll see if it picks up over the sound of the exhaust itself Reading more last night I think it's the wastegate that's open on startup making it so loud, not the valve. So may be related to that more so.
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11-01-2017, 10:41 PM	#4
Mosely Lieutenant 594 Rep 450 Posts Drives: '18 M2 \| '20 X5 \| '07 E92 Join Date: Mar 2017 Location: SoCal iTrader: (1)	Not the greatest audio but just for context, the audio picks up right after the initial loudest 8-10 seconds of the cold start (this was too loud for the mic), where it gets slightly quieter, and then at 15-16 seconds you can hear it go into normal idling. You can clearly hear the metallic ringing noise in this middle period. I assume the first 8-10 seconds of cold start is open wastegate and then that closes and the valve stays closed/open (?) for the next 5-10 seconds before it gets quiet. The metallic noise happens from initial startup to when the valve changes. It's not coming from the engine bay at all and appears to be loudest right at the downpipe/midpipe area but I can't really localize it. Any ideas? Edit: this is a 2018 m2 with 1300 miles, no other mods.
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11-12-2017, 06:25 PM	#5
Mosely Lieutenant 594 Rep 450 Posts Drives: '18 M2 \| '20 X5 \| '07 E92 Join Date: Mar 2017 Location: SoCal iTrader: (1)	Any thoughts?
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11-12-2017, 07:40 PM	#6
David1 Brigadier General 812 Rep 3,949 Posts Drives: 09 E92 09 X5 Join Date: Mar 2007 Location: Columbus, OH iTrader: (1)	Reinstall it. Something is vibrating. Make sure the v-clamps ate seated correctly. __________________ 2021 M2 Comp Sunset Orange \|Black with orange Stitching Dakota Leather\|Executive Pkg\|DCT
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12-14-2017, 08:18 AM	#9
Mosely Lieutenant 594 Rep 450 Posts Drives: '18 M2 \| '20 X5 \| '07 E92 Join Date: Mar 2017 Location: SoCal iTrader: (1)	Update: the noise is getting louder. Still most prominent in a cold start but I can hear it through the engine noise while driving now. I'm considering taking off the downpipe to see if it changes or goes away. Not really sure what's causing it anymore
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12-14-2017, 09:26 AM	#10
gtaM2 Driver 391 Rep 650 Posts Drives: 2016 M2 BSM 6MT Join Date: Jul 2015 Location: toronto iTrader: (0)	could be anything but how about the end of the long bolt on the clamp? maybe it's hitting something like the metallic under panel?
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12-14-2017, 09:51 AM	#11
AndrewC1989 Brigadier General 10911 Rep 4,541 Posts Drives: 2015 328d xDrive Join Date: Aug 2010 Location: NoVA iTrader: (5) Garage List 2015 328d xDrive [8.75]	start the car while it's on a lift. that should help you find your problem area real quick.
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12-14-2017, 04:22 PM	#14
mike@x-ph.com BimmerPost Supporting Vendor 24091 Rep 190,614 Posts Drives: 07-335/12-328/18-M4/21-M4CP Join Date: Sep 2013 Location: Las Vegas iTrader: (23)	It wont go away on its own, did you check the exhaust valves? __________________ Check out our current sale by clicking on this link! https://x-ph.com/sale/ Phone number 702-494-9435
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12-14-2017, 07:33 PM	#17
Daleb Lieutenant 263 Rep 415 Posts Drives: M2 Join Date: Jul 2014 Location: Uk iTrader: (0)	Most likely the wastegate on the turbo, sports cat just amplifies it over the oem cat.
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12-15-2017, 01:10 AM	#20
Lukeni Private First Class 68 Rep 175 Posts Drives: BMW M2 Join Date: Jun 2017 Location: Switzerland iTrader: (0)	Got this sound too with my 300cpsi catted HJS dp. Sounds normal to me. Might be the open wastegate during coldstart...?
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12-15-2017, 03:30 AM	#22
XProject Private 25 Rep 87 Posts Drives: Car Join Date: Oct 2017 Location: Bay Area, CA iTrader: (0)	I also have that metallic ringing sound at cold start, but after the valve closed, it goes away. The shop installed it. Mine is not as bad as yours. Maybe because of your bad recording and garage parking lot. I didn't notice the metal ring until ~300 miles because my exhaust got a lot louder after awhile (in a good way) lol. That ringing sound is only at the cold start (5-10s). I thought I'm the only one. I just feel sorry for my neighbor when I go to work. I wish I can fix it oh well... Last edited by XProject; 12-15-2017 at 03:40 AM..
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