• If you currently own, previously owned or want to own an Avalanche, we welcome you to become a member today. Membership is FREE, register now!

Cab Hood / Windshield Noise



Just got my new AV and was driving 65-70 mph on a sunny day down a local highway when it sounded like it was starting to rain on my cab hood near the top of the windshield (directly above the visors and along the width of the cab). This was a random sound - like rain - although somewhat metalic in nature. The sound seemed to move from directly above me to the middle and then the passenger side and then back!? - not always this pattern though. Sometimes it would be along the entire width and other times only at one or two places. It starts slowly (building vehicle speed approx 60mph +) and then is fairly pronounced at around 70 mph. I do not have a sunroof, luggage rack or the convenience - just a Z71 with standard custom cloth seats. Any ideas out there?
Also, it finally rained today for the first time since I got the AV - I turned on the wipers and the blades 'hopped' across my windshield like they were 10yrs old. Even at the high speed they wouldn't 'smooth-out'. I wonder if this is covered by warranty - I've only got 450 miles on the truck to date.

Bill V
Check the threads about Bug deflectors and the first CAFCNA magazine...explains how to install the double side tape under the window trim...
The wiper blades are covered under warranty for 12/12, that is 12 months or 12,000 miles. If you do not have a bug shield installed I would talk to the dealer about that noise also, otherwise see the referenced thread.
If you do not have the bug deflector or bra then I would still bet the window trim is flapping.....have a passenger look at it while driving and you hear the noise..

For the wipers:

Clean the windshield with some lighter fluid or Prepsol or 3M bug, tar, adhesive remover for paint.....

This will clean off any waxes or other gook that may be on the windshield..

then gets some rubbing alcohol on an old terry cloth rag and wipe the blades until the rag stops turning black....This is oxidized rubber.....

Then apply a light amount of 303 aerospace protectant or similar to the blades and then wipe them with another clean terry cloth towel to remove excess...

303 also makes some wiper blade treatment thingys you may want to look at....


Take it to the dealer >:D
Yes I do have a GM AV taped & screwed on bug shield plus the window vent visors. Perhaps it is the windshield trim 'a-flapping-in-the-wind'. I'll try the posted articles corrective measures and see if this works. Thanks for all of your input.
My brand new truck just did this this weekend.  BUT...only when the temp dropped below 10 degrees.  As I hit small bumps in road - this popping came on - exactly like you said......large rain drops along the top of the windshield above the visor.  I do not have a bug deflector. 

Appreciate anything you find out.