TennisFreak

Searched the forums but did not find anything related to this specifically so I wanted to start a thread to see if anyone else has had this problem or might have a recommendation for me.

Just picked up my M7 Z51 last Thursday and have about 260 miles on her.

This Sunday evening I noticed a buzzing that started coming from behind my left ear.
The buzzing seems to be directly related to a exhaust frequency. I have my exhaust set to track mode so anytime it gets above 1700 RPM's it gets throaty.

When the exhaust opens up all the way to about 3000 RPM's a buzzing comes from the drivers side rear window area. Its very annoying.

It only happens when the exhaust opens up and goes away either when the exhaust is quiet or if I accelerate hard.

I know for sure that the buzz is coming from the drivers rear window area because when the buzzing is happening I reached my arm back there and placed my hand on the window frame.
When I did this, the buzz went away and when I removed my hand it came back.

This is very annoying and I am debating if I should take it in to get looked at or not.

I dont really want them tearing my new car apart if I can avoid it.
I was hoping that if I gave it some time maybe it would go away.

It sounds stupid but on my last car (FR-S) I had some pretty annoying rattles behind the dash that I never had looked at and they actually stopped after a period of time.

Your experiences and opinions would be greatly appreciated.

bob guzzy

See if you can make the piece move by tapping on it.


My guess is it's one panel touching another possibly wedge a piece of foam between them well out of sight.

Like you I wouldn't take it back for something like that, I'm afraid they would make a mess of it trying to do the same thing you need to do.

aj98

The C5 had styrofoam spacers/insulation in the upper rear of each door panel. When the glue breaks down or otherwise separates, there is a buzzing noise from that area.

Given that, it would not surprise me if there was something similar behind the body panels on the C7.

RicK T

This might be the problem:

https://www.corvetteforum.com/forums...or-squeak.html

TennisFreak

Thanks for the tips everyone.

I'm going to look tonight and see if I can pinpoint exactly what is causing it.

RussM05

I started that thread. I still have a buzz that starts over 65 mph that I haven't pinpointed despite pulling off the interior panels a dozen times.

The panel that surrounds the rear side windows is actually 2 pieces sonic welded together. Some of the welds are loose so I glopped alot of silicone caulk around but that didn't fix it. I've never been able to push on any panel that stops it.

The fact the OP has pushed on the panel is huge in pinpointing the buzz. At least he can narrow it down to that area. Pulling off the panels is no biggy. But you have to pull down the halo panel, unbolt the chrome "D" rings, and then pull off the bottom section, then the top. Except for the "D" rings, everything is just attached with clips.

RicK T

That's a bummer.

I don't have a C7 so I'll just ask, is there any chance the high speed buzz might be the windshield cowl, like the problem the C6's had?

fredmills

About a year ago, there was a detailed thread about a side window buzz, and a fix with Velcro, etc. It was a yellow C7 in the pictures and sounds exactly like your problem.

Vetteman Jack

Good luck getting it fixed. If you can't figure it out, take the car in to the dealer for a warranty repair if the noise is really annoying.

3 Z06ZR1

My 2014 had the problem on both sides from the back below the side
windows. 2015 has none.

aj98

Another variable is the speaker grille. Perhaps it's not fitting quite right...since it is so close to the window, pushing on the trim around the window might stop the buzz.

TennisFreak

Ok I found exactly what the cause of the buzzing was.

The plastic frame of the rear window is not sealed flush against the base underneath.
Along the bottom it is sitting up slightly and I am hypothesizing that the deep exhaust note is causing the loose plastic to vibrate.

To test this I put a folded shop paper towel in between the frame and window. The buzz went completely away.

So my next task is to figure out why/how this is not flush against the frame like the other side.
Then how to secure it back down permanently.

Any input would be greatly appreciated.

My first thought is that this could have been caused by the dealership when they installed the window tint.

RussM05

Here is a thread showing the back side of that panel.

https://www.corvetteforum.com/forums...g-rattles.html


Here are a few ways to fix this.

1) Insert a strip of Velcro (the loop part) between the plastic and window. You may be able to do this without removing the panel but it would be tough since the Velcro has a sticky side. You may be able to slide a couple of small pieces between the glass and plastic with the sticky side toward the plastic. But you may be able to see it.

2) Remove the panel and shave 1/8" the plastic edge to increase the gap. Tricky to know how much to shave.

3) Add a strip of black silicone caulk between the plastic and window. This is tricky also because its difficult to control how much. To make a perfect seam, mask the glass and plastic with painter's tape, put silicone caulk down, run a finger over it to push it in the gap, then remove the painter's tape.

4) "U" channel rubber over the edge of the plastic. Get some small rubber hose, split it, then insert it over the plastic edge. Maybe just a piece or two. Best if you pull the panel away from the window by first removing the bottom trim panel and just pulling the upper panel away from the window from the bottom edge. To remove the bottom panel, you have to unbolt he "D" ring. It has a plastic cover over the torx bolt. Then just start pulling it off. Held on with clips.

On my passenger's side, that plastic frame was not firmly plastic welded to the cloth covered panel. It attached with a series of posts and they were loose. So I melted the plastic more and added a thick layer of black silicone caulk over the seam from the back side.



I'm going to check my passenger's side again. I did shave the plastic edge a little but maybe not enough.