Exhaust leak sound while under load

Marv88 · June 4, 2018

14 minutes ago, geswek said:

Can you post it to IG?

I'll follow you -- I want to see if that's same.

Mine isn't at cold startup; it's when I'm driving and I go up hill and press on gas bit to about 1700ish (just before it shifts) and it starts sounding like someone is rattling a can full of marbles until truck downshifts and it goes away.

Mine mainly does the marbles noise on startup and I'm not sure if the noise I hear on certain acceleration situations is the same (from other threads I've read here I think that may be the flapper valve) I'll post the clip on IG in a minute.

DONWT15 · June 4, 2018

45 minutes ago, Blk17Machinep said:

Ford and dodge sadly.

They make fun of everyone and then copy it.

Dodge half back doors next thing u know Chevy has a “double cab”

ford with the v6 turbo here comes Chevy with a turbo.

Ford with aluminum, Chevy has spent so much money bashing aluminum is the only reason the new truck isn’t all aluminum.

list goes on.

Why do we still have a key? My 2010 Altima was push start.

Wont be buying another gm product. My neighbor bought a ct6 one of the first in country and that thing is always in the shop.

This Chevy is my first and last. My 5.3 ticks like it has aids

Had a 1999 Sierra with half back doors so GM has had them at least 19 yrs.

Ford did beat them with the turbo

Aluminum costs a lot more than steel and Ford has a partnership with Alcoa, but they are still looking for the "payoff" it has cut into their profitability.

Push button starts are a waste of money. Just a gimmick. You still have to get in the vehicle to start it. Still have to carry a FOB to do anything.

Feel sorry for your neighbor. We all get a junker once in a while.

Good luck with your next vehicle.

Edited June 4, 2018 by DONWT15

Marv88 · June 4, 2018

52 minutes ago, geswek said:

Can you post it to IG?

I'll follow you -- I want to see if that's same.

Mine isn't at cold startup; it's when I'm driving and I go up hill and press on gas bit to about 1700ish (just before it shifts) and it starts sounding like someone is rattling a can full of marbles until truck downshifts and it goes away.

Just posted the video. I'm going to clamp the flapper valve to see if that noise and/or the one under acceleration situations like yours goes away

geswek · June 4, 2018

Just posted the video. I'm going to clamp the flapper valve to see if that noise and/or the one under acceleration situations like yours goes away

I don’t have flapper valve. It’s custom exhaust with AFM disabled.

Sent from my iPhone using Tapatalk

DONWT15 · June 5, 2018

Good luck with your next vehicle.

iwannaseeatnight · June 5, 2018

19 hours ago, Marv88 said:

I think there is more than one noise being discussed here. I have the exhaust leak noise on the passenger side and the "marbles in the can" on the drivers side. I just made a clip of the sound on cold start up but don't know how to post it.

I have the exhaust leak, but the sound is coming from the driver's side floor. The sound could be traveling, however, passengers say they don't hear it. I have a recording, but the file is far beyond the 4.88MB limit.

geswek · June 5, 2018

I have the exhaust leak, but the sound is coming from the driver's side floor. The sound could be traveling, however, passengers say they don't hear it. I have a recording, but the file is far beyond the 4.88MB limit.

Any chance you can upload it to free hosting site and send link? I want see if that’s what I got.

It’s definitely coming from drivers side.

Sent from my iPhone using Tapatalk

spenpet · June 5, 2018

following...

I have both sounds...the air leak, exhaust sound comes from driver side door, near the floor board...the marbles seem to come from the middle of the truck under the firewall...and i agree, it sounds like detonation...

how does the exhaust leak affect the truck/performance?

geswek · June 5, 2018

27 minutes ago, spenpet said:

following...

I have both sounds...the air leak, exhaust sound comes from driver side door, near the floor board...the marbles seem to come from the middle of the truck under the firewall...and i agree, it sounds like detonation...

how does the exhaust leak affect the truck/performance?

Are you tuned? and by who?

I have that exact noise by the firewall. I did run log file and I don't see any heavy knock retard--about 1.0 or so.

mferry22 · June 5, 2018

I got my truck back from the dealer, they could not duplicate the sound but they said GM is aware of the issue but has no fix right now. The noise I have is on the driverside by the door/ footwell area and sounds like an exhaust leak. It only happens during light to moderate acceleration right around 1800 rpms. As soon as I got on the highway I heard the noise. I did notice if I drive in M5 it doesn't make the noise. Could it be something to do with the transmission? I have the range device so its not that and I had the flapper valve removed.

geswek · June 5, 2018

1 minute ago, mferry22 said:

I got my truck back from the dealer, they could not duplicate the sound but they said GM is aware of the issue but has no fix right now. The noise I have is on the driverside by the door/ footwell area and sounds like an exhaust leak. It only happens during light to moderate acceleration right around 1800 rpms. As soon as I got on the highway I heard the noise. I did notice if I drive in M5 it doesn't make the noise. Could it be something to do with the transmission? I have the range device so its not that and I had the flapper valve removed.

I have tune with AFM disabled (same as Range, had one previous to my tune). I get the same issues; it seems to occur when I'm around 1800 rpms and I push on gas just a bit to where it wants to shift but doesn't (lug engine on incline). I hear the rattling noise.

I was going to at one point load the Diablo base tune and see if it happens; but since you have no tune and hear it -- that makes me question something else.

mferry22 · June 5, 2018

I also had a 2018 Sierra with 18 miles on it for a loaner all weekend. I put 500 miles on it and it didn't make the noise at all. It had the 5.3 in it but I don't know what tranny it had. It was an SLE.

geswek · June 5, 2018

8 minutes ago, mferry22 said:

I also had a 2018 Sierra with 18 miles on it for a loaner all weekend. I put 500 miles on it and it didn't make the noise at all. It had the 5.3 in it but I don't know what tranny it had. It was an SLE.

I don't recall ever hearing it when I had AFM on.

I'm wondering if having AFM disabled makes it possible to hear it.

mferry22 · June 5, 2018

Mine is a little worse with AFM active. When I have my range device plugged in, its not as bad.

spenpet · June 5, 2018

1 hour ago, geswek said:

Are you tuned? and by who?

I have that exact noise by the firewall. I did run log file and I don't see any heavy knock retard--about 1.0 or so.

no tune...just factory...