This is the strangest sound I've ever heard. It sounds like a high pitch whistle. I only hear it during idling and low speeds. It is not affected by engine RPM, Transmission engaged or in Park, AC on or off. It is difficult to determine if it is a vacuum whistle or high pitched mechanical sound. I've crawled under the van while idling and could not pinpoint it but it is coming from the back half of the vehicle. Naturally, it doesn't make the sound all the time and is difficult to locate. It isn't a consistent sound but varies like a child with a 'flute'.

Any ideas?

 

<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <wontGrowAutofit/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]--> I would recommend taking the vehicle to the dealership, especially if you are still under warranty. They will be able to diagnose the whistling noise that you are hearing. They will also be the best to go through for fixing it, as well, because there are part and labor warranties for work done that the dealership. Good luck.
Breanne
Chevrolet Customer Assistance

 

If it is under warrenty, yes take it back. If not, the symptoms you describe are or dould be an air leak in the back cabin.

 

It doesn't sound like an air leak and it is coming from underneath the van. It is under warranty and I'm taking it to the dealer tomorrow. I'll post what they found here.

 

Hello,
Did you ever find out what that sound was?

 

Do you have friends that like to joke around?