The infamous dash buzzing (windshield cowl) problem
Race Director
Joined: Oct 2005
Posts: 14,999
Likes: 200
From: Bay Area Ca.
My statement "new improved" was made somewhat tongue in cheek.
The new cowl does seem to be configured slightly different, though. The lip against the windshield feels stiffer especially at the flex joint. It is positioned at an angle against the glass instead of laying flat as the old one. That would reduce it's tendency to vibrate I would think.
Hard to tell from a photo or I would put some up. The finish on the new one is smoother also. Whether these perceived differences
are from better quality control or an actual change in the manufacture, I don't know. So far no buzzing with the new one. The old one buzzed 'till I put some adhesive on it.
The new cowl does seem to be configured slightly different, though. The lip against the windshield feels stiffer especially at the flex joint. It is positioned at an angle against the glass instead of laying flat as the old one. That would reduce it's tendency to vibrate I would think.
Hard to tell from a photo or I would put some up. The finish on the new one is smoother also. Whether these perceived differences
are from better quality control or an actual change in the manufacture, I don't know. So far no buzzing with the new one. The old one buzzed 'till I put some adhesive on it.
Wishful thinking on y part.
Racer
Joined: Jan 2007
Posts: 462
Likes: 3
From: Plainview New York
Had the cowl changed today for the second time. In both cases the part number is the same # 25778761. On this install the tech used double sided tape but not on the lip that rests against the windshield, it had the 5 clips and some pushpins on the side but it seemed identical to what was removed. My first change was in July 2012 and then today. Hopefully this one will last. By the way the noise started back in October of 2012 but since I was storing for winter I waited for spring. I played the radio loud on the way home didn't hear a thing.
Race Director
Joined: Mar 2007
Posts: 11,083
Likes: 29
From: Murfreesboro TN
Melting Slicks
Joined: Dec 2006
Posts: 2,694
Likes: 106
My question now is this: Do any of the factory cowls have that middle clip installed at all??? Since cars from '08s to '12s have it missing, wonder if it's been missing all along. Maybe it doesn't line up with the hole in the car or something. My '12 GS doesn't seem to make noise there (but has a ton others 
) now, but want to know what to expect when it does. I'd be nice to see pictures 
. Seems to me just installing that middle clip should solve all issues, right?
) now, but want to know what to expect when it does. I'd be nice to see pictures . Seems to me just installing that middle clip should solve all issues, right?
Racer
Joined: Jan 2007
Posts: 462
Likes: 3
From: Plainview New York
My question now is this: Do any of the factory cowls have that middle clip installed at all??? Since cars from '08s to '12s have it missing, wonder if it's been missing all along. Maybe it doesn't line up with the hole in the car or something. My '12 GS doesn't seem to make noise there (but has a ton others ) now, but want to know what to expect when it does. I'd be nice to see pictures . Seems to me just installing that middle clip should solve all issues, right?
) now, but want to know what to expect when it does. I'd be nice to see pictures . Seems to me just installing that middle clip should solve all issues, right?
Pro
Joined: Aug 2008
Posts: 674
Likes: 3
From: Milky Way
I had the recall completed on mine last Saturday. It hadn't made any noise but I figured I should do it. Now there is a sort of a buzzing noise when dring in the interstate, I'm thinking I should have left it alone and now I have an issue.
I know, I messed up.
I know, I messed up.
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Race Director
Joined: Oct 2007
Posts: 11,367
Likes: 211
From: Edgewood Washington
St. Jude Donor '11-'12-'13-'14-'15
Heel & Toe
Joined: Dec 2008
Posts: 21
Likes: 0
From: Arlington TX
I checked with a Chevy dealer for a TSB on my VIN number. No TSB's have been issued for my '07 Z06, so I walked to the parts department and bought a new cowl "screen". They had it in stock - cost ~$85. I spent an hour or so replacing the original screen. I suspect that GM will replace it at no charge if the Vette is still under its bumper-to-bumper warranty.
It seems that the new one is much stiffer along the passenger side edge. I didn't use any adhesive, so I'll see if the buzzing has been eliminated. I used a battery terminal puller to remove the driver side wiper arm (after removing the 15mm nut on each arm) and a heavy duty trim tool to remove the passenger side (don't pry against the glass). Use small needle nosed pliers to depress the pins on the washer fittings to back them out of the old screen. Gently remove the hoses from the fittings (a firm and steady pull removes the hoses from the barbed fittings).
It seems that the new one is much stiffer along the passenger side edge. I didn't use any adhesive, so I'll see if the buzzing has been eliminated. I used a battery terminal puller to remove the driver side wiper arm (after removing the 15mm nut on each arm) and a heavy duty trim tool to remove the passenger side (don't pry against the glass). Use small needle nosed pliers to depress the pins on the washer fittings to back them out of the old screen. Gently remove the hoses from the fittings (a firm and steady pull removes the hoses from the barbed fittings).
Thread Starter
Pro
Joined: Jun 2011
Posts: 597
Likes: 257
From: Michigan
I am happy to see the thread added to the faq. Though I was happy to have the noise gone (man it is a terrible noise), I was really irritated that I bought an unnecessary $80 part and took quite a few things apart that didn't need to be touched.
Glad to see it may save some others the trouble.
Checking for the clips under the weatherstripping is really simple, and I would do that even if you had yours replaced under warranty. If the clips were not there to start with, then the tech probably won't replace them. No clips = more vibration and I have no doubt that could result in more frequent tears of the rubber lip side.
Glad to see it may save some others the trouble.
Checking for the clips under the weatherstripping is really simple, and I would do that even if you had yours replaced under warranty. If the clips were not there to start with, then the tech probably won't replace them. No clips = more vibration and I have no doubt that could result in more frequent tears of the rubber lip side.
Advanced
Joined: Jan 2013
Posts: 63
Likes: 1
From: Morrisville NC
As two people mentioned above, there is a recall for it for me GS. The day I got mine, my dealer told me about the recall. It was fixed 20 minutes after the part arrived. Mine was making the noise before, but not after the replacement. I have a 2013, I can only assume the rest of you checked with a local dealer to see if revere is a recall for the earlier models?
Instructor
Joined: Sep 2012
Posts: 163
Likes: 0
From: NC
At what speed does this buzzing start? Does it really not start until 75-80 mph?? I have a 08 convertible. I'm not sure I understand where the tears start. I looked to see if I could see any problems on mine. Mine is missing the center clip and where the cowl meets the windshield in front of the HUD, the width of the HUD, it is not tight against the windshield, it is raised about 1/8". What should I do?
Heel & Toe
Joined: Dec 2008
Posts: 21
Likes: 0
From: Arlington TX
The "buzzing" only appears at highway speeds when the A/C is not in recirculate mode. The new part, which I installed (see my post below), fits snugly along the entire lower windshield with NO gaps. I didn't add a center "clip" to my install because I don't believe that's the problem. I've never heard of a buzz from any other location other than the passenger side (and that side does have 2 "clips" there - equally spaced). The new part seemed to be a bit thicker on the passenger-side edge than the original one removed, so (hopefully), the buzz won't recur at some point in the future. Yes, black electrical tape will work to eliminate the buzz, but that looks very tacky. This is not an expensive or difficult fix.
Melting Slicks
Joined: Dec 2009
Posts: 2,749
Likes: 50
From: Westmont Il.
The wiper did not want to just pop off, as some have said it does, probably my being too timid. Anyway, I was paranoid of ruining something so I made a special mini puller that worked fine.
Melting Slicks
Joined: Jun 2001
Posts: 2,670
Likes: 9
From: Rochelle Illinois
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