My 07 Silverado NBS has developed a whistle

Hello,
 
I am a newbie to the Forum and would like some advice.  In April, I purchase a NBS 2007 Silverado ext. cab.  Love the truck!  But last week, on the highway I have noticed a whistling sound coming from the passenger side.  Almost sounds as if the window is partially down, or the door isn't closed all the way.  Checked all this, and both are closed all the way.
 
Any suggestions???  Thanks for the help, glad I found the forum.

by chance do you have either a bug deflector or vent shades installed?  i had some on my crew cab, and they created the same simptoms you described.  so i took it to the dealer and they said that the vent shades were installed incorrectly.  i removed them, and sure enough the whistling went away.

quote:

ORIGINAL: 08silveradonb

by chance do you have either a bug deflector or vent shades installed?  i had some on my crew cab, and they created the same simptoms you described.  so i took it to the dealer and they said that the vent shades were installed incorrectly.  i removed them, and sure enough the whistling went away.

 
Forgot to mention, no bug deflector or vent shades.  Just as it came from the factory 

Check your door seal.  May be out of place or pinched etc.

Also might try folding your mirror in and driving to see if the whistle is coming from it.
 
Can you get someone to ride with you to see if they can pinpoint the whistle?

I have the same problem and I can't find it anywhere.

I also had the same problem on my 03 silverado.  I couldn't find the source anywhere.  All of a sudden it just went away on its own

Had the same problem on mine.  I tool it to the dealer and there was a bulliten out from GM.  They instaled a foam insert between the mirror and the door.  It did the trick.

Dealer finally found the problem.  The headlight assembly on the passenger side was out of alignment, and the air was whistling through the fender and into the cabin.  They moved the assembly back into place, about 1/2 inch, and no more whistle