Loud rattling sound coming from rear of car after Cora Extreme Exhuast

carlythecamaro · 12-06-2022, 12:03 AM

hey all, new to this website but i'm having an issue with my car hoping someone can help. recently just had a corsa extreme exhaust installed with texas speed headers, got the proper tune but noticed on cold start & with i give it gas below 1500RPM there's this awful loud, rattle/ banging noise. took it back to the shop and was told that maybe i have a loose exhaust valve? i have provided a link to my cold start, any help would be much appreciated

http://youtube.com/shorts/m3-JcsPUelw?feature=share

Aaron07 · 12-06-2022, 03:07 AM

I would take it back to the whomever you had do the install and ask them to figure it out. Even if you have to pay them.

mrgto · 12-06-2022, 06:02 AM

I wouldn't trust a shop that told me I had a loose exhaust valve. Find another mechanic and get it on a lift.

easttxss · 12-06-2022, 09:13 AM

Quote:

Originally Posted by mrgto

I wouldn't trust a shop that told me I had a loose exhaust valve. Find another mechanic and get it on a lift.

I think they mean the AFM or NPP exhaust valves in the pipes.

It should be easy to locate that from under the car.

mrgto · 12-07-2022, 12:59 PM

Quote:

Originally Posted by easttxss

I think they mean the AFM or NPP exhaust valves in the pipes.

It should be easy to locate that from under the car.

Aren't the valves in the muffler?

19RSVert2.0T · 12-07-2022, 02:10 PM

That sounds a little extreme, but sometimes the mufflers will rattle as they are breaking in. I’ve had that with previous exhausts I’ve installed on my own cars and thought something was loose. Would check and everything was good and tight then it would go away in a couple days.

easttxss · 12-07-2022, 03:14 PM

Quote:

Originally Posted by mrgto

Aren't the valves in the muffler?

NPP valves are at the exhaust tips, AFM valves are in the pipes (if it even has them).

carlythecamaro · 12-08-2022, 11:36 AM

Quote:

Originally Posted by 19RSVert2.0T

That sounds a little extreme, but sometimes the mufflers will rattle as they are breaking in. I’ve had that with previous exhausts I’ve installed on my own cars and thought something was loose. Would check and everything was good and tight then it would go away in a couple days.

its been going on for over a month now

FlukeSS · 12-08-2022, 03:19 PM

I wasn't going to say anything, in my case rattling was the X-Pipe settling against the Cross Member brace. Its an easy enough fix and my shop did it for free as they did the initial install. They also said all Camaros have that issue with the X-Pipe settling and rattling against the Cross Member Brace

I did watch your video and it doesn't exactly sound like the same issue I had. I am not sure if that is applicable in your build I didn't see you specify an X-Pipe upgrade.

carlythecamaro · 12-09-2022, 01:21 PM

Quote:

Originally Posted by FlukeSS

I wasn't going to say anything, in my case rattling was the X-Pipe settling against the Cross Member brace. Its an easy enough fix and my shop did it for free as they did the initial install. They also said all Camaros have that issue with the X-Pipe settling and rattling against the Cross Member Brace

I did watch your video and it doesn't exactly sound like the same issue I had. I am not sure if that is applicable in your build I didn't see you specify an X-Pipe upgrade.

ive noticed that it also rattles in 8th gear if im under 1500 RPM, any other gear its fine, i was told it might be caused by high pressure exhaust flow which i have no idea how to fix.

FlukeSS · 12-09-2022, 02:31 PM

Quote:

Originally Posted by carlythecamaro

ive noticed that it also rattles in 8th gear if im under 1500 RPM, any other gear its fine, i was told it might be caused by high pressure exhaust flow which i have no idea how to fix.

For me: It rattled at regular RPM levels and usually around the same RPM levels. It would smooth out disappear at high RPM, but show its face at lower accel mid level RPMs, and not lower RPM's. In my case call it an RPM sweet spot I guess where it would rattle. It would even make it sound like the exhaust was louder than it actually was.

High Pressure exhaust flow. As I'm no expert would need to be defined for me. At first guess, it could be an exhaust leak like others have said. Rattle is Rattle, it can have different tones, and sounds. In my case the rattle literally sounded like metal bouncing on metal with the right RPM levels.

carlythecamaro · 01-18-2023, 10:14 PM

Quote:

Originally Posted by FlukeSS

For me: It rattled at regular RPM levels and usually around the same RPM levels. It would smooth out disappear at high RPM, but show its face at lower accel mid level RPMs, and not lower RPM's. In my case call it an RPM sweet spot I guess where it would rattle. It would even make it sound like the exhaust was louder than it actually was.

High Pressure exhaust flow. As I'm no expert would need to be defined for me. At first guess, it could be an exhaust leak like others have said. Rattle is Rattle, it can have different tones, and sounds. In my case the rattle literally sounded like metal bouncing on metal with the right RPM levels.

Thats exactly what it sounds like, at certain times it seems as if the exhaust sounds louder than it actually is.

Hostile_1LE · 01-18-2023, 11:34 PM

It’s probably the exhaust rubbing against the tunnel brace. When I installed mine, it rubbed and it was LOUD.

FlukeSS · 01-19-2023, 08:05 AM

Quote:

Originally Posted by carlythecamaro

Thats exactly what it sounds like, at certain times it seems as if the exhaust sounds louder than it actually is.

Quote:

Originally Posted by Hostile_1LE

It’s probably the exhaust rubbing against the tunnel brace. When I installed mine, it rubbed and it was LOUD.

^

Had same issue when I had my X-Pipe installed. My shop shimmied the brace and I never had the issue again.

12-06-2022, 12:03 AM	#1
carlythecamaro Drives: 2017 Camaro SS Join Date: Nov 2022 Location: Indiana Posts: 53	Loud rattling sound coming from rear of car after Cora Extreme Exhuast hey all, new to this website but i'm having an issue with my car hoping someone can help. recently just had a corsa extreme exhaust installed with texas speed headers, got the proper tune but noticed on cold start & with i give it gas below 1500RPM there's this awful loud, rattle/ banging noise. took it back to the shop and was told that maybe i have a loose exhaust valve? i have provided a link to my cold start, any help would be much appreciated http://youtube.com/shorts/m3-JcsPUelw?feature=share

12-06-2022, 03:07 AM	#2
Aaron07 Drives: 2017 2SS F1FTY Join Date: Feb 2020 Location: Fort Wayne, IN Posts: 348	I would take it back to the whomever you had do the install and ask them to figure it out. Even if you have to pay them. __________________ 2017 2SS F1FTY/HUD/Mag Ride/NPP/Nav/M6/Mishimoto catch can/BTR stage 2 Cam kit/GPI ported LT2 IM and 95mm TB/Roto Fab CAI/Kooks Long Tubes ceramic coated/Borla S Type NPP catback/AFE lowering springs/1LE wheels/OEM smoked tail lights/Diode Dynamics side markers/Uniden R7/3D Maxpider floor mats/Adams graphene ceramic coat

12-08-2022, 03:19 PM	#9
FlukeSS Drives: 2020 Camaro 2SS A10 Join Date: Jun 2018 Location: Michigan Posts: 1,386	I wasn't going to say anything, in my case rattling was the X-Pipe settling against the Cross Member brace. Its an easy enough fix and my shop did it for free as they did the initial install. They also said all Camaros have that issue with the X-Pipe settling and rattling against the Cross Member Brace I did watch your video and it doesn't exactly sound like the same issue I had. I am not sure if that is applicable in your build I didn't see you specify an X-Pipe upgrade. __________________ 2020 Camaro 2SS A10 \| Rebuilt by: CBI Street Cars \| 2" SE LT Headers \| 3" SE X-Pipe \| 3" MBRP Axle-Back \| Pri & Sec Cat Deletes \| K&N Typhoon CAI \| LT2 Ported \| 95mm ZR1 TB \| DOD Delete \| BTR Stage I Cam \| ECM, TCM & E85 \|Tuned by: Shane Hinds \| Dyno: 510 rwhp 472 rwtq

12-06-2022, 06:02 AM	#3
mrgto Drives: '10 Equinox LTZ Join Date: Jul 2011 Location: Sarasota FL Posts: 23	I wouldn't trust a shop that told me I had a loose exhaust valve. Find another mechanic and get it on a lift.

12-07-2022, 02:10 PM	#6
19RSVert2.0T Drives: 2019 RS Convertible 2.0T Join Date: Nov 2022 Location: Myrtle Beach, SC Posts: 5	That sounds a little extreme, but sometimes the mufflers will rattle as they are breaking in. I’ve had that with previous exhausts I’ve installed on my own cars and thought something was loose. Would check and everything was good and tight then it would go away in a couple days.

01-18-2023, 11:34 PM	#13
Hostile_1LE Drives: 2020 Camaro SS 1LE \| Satin Steel Join Date: Jan 2022 Location: Lubbock, Tx Posts: 137	It’s probably the exhaust rubbing against the tunnel brace. When I installed mine, it rubbed and it was LOUD.

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