GMT900 high road noise in rear of crew cab?

[Stumpuller6.5]

my salesman did a curtesy call today and i mentioned the interior noise, he put me through to the service advisor, she noted that gm currently does not have a fix for this? and that it affects about 20% of 2010 CC models mostly?!?!? they said they have torn down 2 trucks latley and did major re-isulations in the interiors to no avail. she said to keep checking in to see if they have develped a fix for this.

So i guess when i have some time i`l start experimenting. as many have noted above it seems changes to the interior net no results, so maybe i`ll try making up some sort of sound deflection devices under the truck.

any ideas on the subject???

 

[Bigredmariner]

Dual exhaust with flowmaster 10's should quieten it down.

 

[ScottyBoy]

Try duct tape or metal tape over the vents?

 

[ScottyBoy]

my salesman did a curtesy call today and i mentioned the interior noise, he put me through to the service advisor, she noted that gm currently does not have a fix for this? and that it affects about 20% of 2010 CC models mostly?!?!? they said they have torn down 2 trucks latley and did major re-isulations in the interiors to no avail. she said to keep checking in to see if they have develped a fix for this.

So i guess when i have some time i`l start experimenting. as many have noted above it seems changes to the interior net no results, so maybe i`ll try making up some sort of sound deflection devices under the truck.

any ideas on the subject???

And that 20% is only the people who filed complaints about it. It may be a lot more than that.

 

[vansdonk]

I know my trucks rain gutter drainage system causes it to seem like I have a rear door open or something while driving on wet roads. But there isn't really anything to do about it except block off the drain tubes and rain gutter. So I just turn up the radio. And if I have a passenger that doesn't "get it", I just tell them that they need to jump out and check the doors. After about the third or fourth red light, they get it.

 

[Stumpuller6.5]

Dual exhaust with flowmaster 10's should quieten it down.

yup "sound deflection devices"

And that 20% is only the people who filed complaints about it. It may be a lot more than that.

i know the one i test drove was not as loud as this...

I know my trucks rain gutter drainage system causes it to seem like I have a rear door open or something while driving on wet roads. But there isn't really anything to do about it except block off the drain tubes and rain gutter. So I just turn up the radio. And if I have a passenger that doesn't "get it", I just tell them that they need to jump out and check the doors. After about the third or fourth red light, they get it.

nice, i bet my wife would give me "the look" if i told her to go check.

 

[Stumpuller6.5]

Okay so i talked to the service manager from my dealership, they appeared to be not aware of the TSB. However they investagated it and have been told that the upgraded insolation is not yet available, ( iguess on top of the changed rubber and sealant, they also are putting in thicker sound material) but will be available within the month.

(do note i`m located in canada and getting things may be slower than US.)

So i will be in touch with them soon, if they don`t call me first. they put a note in my file over my consern. so hopefully they do their part to resolve the problem.

 

[Stumpuller6.5]

Contacted them and would have made an appointment but they claim they have tried this latest TSB and it does not satisfy the customers and the cab is still noisy.

anybody have any engineering ideas?

I read several threads all over the internet, there is no solid fix yet!!!

 

[Darkanion]

If you wanted a quiet vehicle, you should've gotten a car!

On a more serious note, could you get someone to drive the truck while you get in the back seat area and snoop around for where the "most" noise seems to be coming from? Maybe that would give you some ideas for how to fix it.. or at least where to be focused on for a fix..?

 

[Stumpuller6.5]

i was going to experiment with placing something on top the frame tucked under the cab and box to see if deflecting or rejecting sound waves from the road would help. i do beleive with the canopy it is much worse...