Jaydubgt

I have a 2013 60th Anniversary Grand Sport 6M Coupe with the 4LT blue interior and about 17k miles. I've had it since this past October.

For about a month now, when it's in the morning (like going to work) and I'm on the freeway at 75-80mph, the dashboard emits a buzzing sound. It's loud enough that I noticed it above the music I had on. If I drop below about 65mph, the sound goes away. After driving for about 20~30 minutes the sound goes away totally, regardless of speed.

At first, I thought it was coming from the vents. But the noise was further forward than that. But just in case, I played with all the HVAC buttons with no change. It seems to be coming from the base of the windshield. I put my hand on everything I could, to chase down the buzzing, but still no change.

The noise seems to be related to speed and maybe heat, assuming that things heat up enough after 20~30 minutes to stop the noise. As I’m writing this, I wonder if the noise is coming from the front mask (bra) I have on the car. However, I’ve had that on the car a few months before the noise showed up. Next time it happens, I’ll roll down the window to see if the noise is coming from outside. However, it sure sounds like it’s on the inside.

Maybe wind noise from the top? I push up slightly on the inside of the top when the noise is going, but there’s no change.

Any other ideas would be appreciated.

Thanks, guys and gals!!

RogerRamjet21

I'm guessing it's the cowling. Look at the cowling in front of the glove box area where the rubber part meets the windshield and see if there isn't a split forming where the rubber part of the cowling bonds to the plastic part. The good news is the part is still available and costs about $89.00. The procedure to replace it is pretty easy with the hardest part getting the wipers off the stalks (just use penetrating fluid and wait a while instead of buying a puller and finding out it isn't deep enough - ask me how I know). The sound has been described as an angry can of bumble bees in the glove compartment and it usually starts about 65mph, also worse the lower the temp. I'll see if I can find my thread on it.

RogerRamjet21

One more thing. I marked the wiper position on the windshield with tape, but that is not a great way to do it IMO. If I have to do this again, I would mark a line across the wiper base and stalk before removing the wipers and replace on the same line.

RogerRamjet21

Here is the thread I referenced: Cowling replacement

Frankie15

Roger is right. This is likely the cause. You can be 100% sure by taping the cowl where it meets the glass. If the sound goes away, you found your culprit. Check this thread for more info:

https://www.corvetteforum.com/forums/c6-corvette-general-discussion/3261348-the-infamous-dash-buzzing-windshield-cowl-problem.html

RogerRamjet21

Clicky

Jaydubgt

Thanks, guys!

I'll take a look at it this weekend!!

John

Jaydubgt

Hey Guys,

I tucked a small square of double stick tape and the noise went away!!

Thanks, guys! I had dollar signs in my eyes thinking about how much it would cost to fix when I first heard the sound.

That's why I love this forum! Everyone is so helpful with quick reply's !!

Vette_Fan

I have the same thing - I won't advise changing the cowl or anything.

Just put a painters tape, packaging tape, or any tape on the plastic cowl where it meets the front glass windshield. Tape it from one end to another. Drive regularly, if the noise goes away, you know that was the problem, which is pretty common. To FIX it, remove the tape, now that the problem is confirmed, and put some epoxy/glue under the cowl to make sure it's glued well with the glass. Noise goes away permanently. .

z06clif

Cowl related. Possibly a leaf or someting stuck in there. Take a piece of duct tape and tape the cowl down and see if that helps. If it does then there lies your problem. If not then youve eliminated the cowl and further investigation is necessary

Clif

CorvetteSparky

In my case it was the HUD bezel. It would stop buzzing on sunny days when it and the dash heated up and expanded a little. On cloudy days or the first part of a drive it would rattle or buzz. I took it off and but a little self-adhesive felt on the bottom side so that it fit tighter and it hasn't made a sound since.