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Some of us would admit the C7 certainly doesn't have the quietest interior. Over the years I have been chasing buzzing and creaking noises all around the inside. I have been successful for the the most part. While I had some panels off, I decided to go the inexpensive route of sound deadening with Frost King self-stick insulation. It was tedious work, but WOW does it make a difference. Anyway, after making it quiet (like my wife's '19 Acura RDX) I have been noticing a new noise coming from behind the passenger-side rear speaker on rough roads at highways speeds. Well, I removed everything including the speaker and asked my wife to drive. I found the noise is the rubber flaps on the "cabin pressure equalizer/vent" behind the speaker. When the car is shaking along in Sport or Track modes, I can see the flaps slapping against the assembly. When I inserted a wooden dowel to open them manually, the noise was gone.
My first fix attempt was using the soft loop side of some velcro. It's better, but not gone. According to the service manual, there's only one "Body Pressure Relief Valve." Otherwise I would glue those flaps down. I may have to live with this issue.
There will surely be many car guys that will roll their eyes at an apparent "obsession." Say anything you want. I am really starting to enjoy my car as I get more up close and personal with her. Making this beauty even more enjoyable to drive is what keeps the love affair going.
This is the view thru the speaker hole...
Here's a sample of the low-cost sound deadening I've done...
Last edited by stevettec7; May 2, 2019 at 06:15 PM.
Some of us would admit the C7 certainly doesn't have the quietest interior. Over the years I have been chasing buzzing and creaking noises all around the inside. I have been successful for the the most part. While I had some panels off, I decided to go the inexpensive route of sound deadening with Frost King self-stick insulation. It was tedious work, but WOW does it make a difference. Anyway, after making it quiet (like my wife's '19 Acura RDX) I have been noticing a new noise coming from behind the passenger-side rear speaker on rough roads at highways speeds. Well, I removed everything including the speaker and asked my wife to drive. I found the noise is the rubber flaps on the "cabin pressure equalizer/vent" behind the speaker. When the car is shaking along in Sport or Track modes, I can see the flaps slapping against the assembly. When I inserted a wooden dowel to open them manually, the noise was gone.
My first fix attempt was using the soft loop side of some velcro. It's better, but not gone. According to the service manual, there's only one "Body Pressure Relief Valve." Otherwise I would glue those flaps down. I may have to live with this issue.
There will surely be many car guys that will roll their eyes at an apparent "obsession." Say anything you want. I am really starting to enjoy my car as I get more up close and personal with her. Making this beauty even more enjoyable to drive is what keeps the love affair going.
This is the view thru the speaker hole...
Here's a sample of the low-cost sound deadening I've done...
Courious, but could you describe the noise? I have a squeaking coming from that area that I notice over rougher parts of the road. I honestly thought that my passenger tail light assembly was loose or something but haven’t had time to really diagnose it yet.
The noise I have now is almost a "popping." It only shows up when I'm on a rough (course) road. The last noise I troubleshot was a chirping like "ercha...ercha..ercha" coming from the quarter panel or rear area. That problem would up being the rear taillights rubbing against the rear bumper cover. I removed the taillights and filed the contact points and added squeak reduction tape made by 3M.
Here's a link to where I found the fix for that....
I am currently adding the sound deadening to my trunk floor too, and I found 3 potential rattle areas.
- The electronic module (Rear Liftgate Control) located in the center, right below the hatch latch, rattles in its mounting bracket. Added some sponge rubber squares between the mounting bracket and the module.
- The loose plastic pushpin fastener that holds the emergency cable coupling box (black plastic) to the metal hatch latch bracket. I replaced the pushpin with a metal screw, washer, and locknut. Somebody else posted that the plastic pushpin breaking is often why the emergency hatch release does not work when the key is used.
- The Keyless Entry control module was not fully inserted into its mounting bracket. This is located at the back, by the rear wall, on the drivers side. Just push the module fully into its slide-in bracket to secure it.
Last edited by ersatz928; May 3, 2019 at 05:52 PM.
I am currently adding the sound deadening to my trunk floor too, and I found 3 potential rattle areas.
- The electronic module (Rear Liftgate Control) located in the center, right below the hatch latch, rattles in its mounting bracket. Added some sponge rubber squares between the mounting bracket and the module.
- The loose plastic pushpin fastener that holds the emergency cable coupling box (black plastic) to the metal hatch latch bracket. I replaced the pushpin with a metal screw, washer, and locknut. Somebody else posted that the plastic pushpin breaking is often why the emergency hatch release does not work when the key is used.
- The Keyless Entry control module was not fully inserted into its mounting bracket. This is located at the back, by the rear wall, on the drivers side. Just push the module fully into its slide-in bracket to secure it.
I’ll check these. Thanks. I still have my rear panels off.
The vent you wrote about, that Velcro reduced but not eliminated the noise.
My hearing is not as acute as yours...haha
I am assuming the noise is the rubber flap impacting the hard plastic (now Velcro).
Time to replace, lubricate or line with felt that rubber flap?
Any other hard to find to rattle you addressed as a memo to our co-members?
Steve, thanks for your posting. I'm sure your detective work might be helpful to some members of the forum with similar problems. I've been lucky so far concerning noises in the cabin. Guess I'm one of the lucky ones.
The vent you wrote about, that Velcro reduced but not eliminated the noise.
My hearing is not as acute as yours...haha
I am assuming the noise is the rubber flap impacting the hard plastic (now Velcro).
Time to replace, lubricate or line with felt that rubber flap?
Any other hard to find to rattle you addressed as a memo to our co-members?
Again I admire your rattle proofing hobby.
I’ll have to remove the rear wheel well lining to get to the vent, so yep, I’ll be back in there eventually.
Today I am doing the sound insulation of the cargo area floor, and have found that almost all of the black 10mm nuts are barely finger tight. These nuts hold the electronic modules and the fuse-block to the cargo floor, and are also found on the 4 Targa-top latches/brackets.
Chasing interior buzzes and creaks
