When I start the Tahoe after it sits i hear a weird grinding noise coming from the fan area when you put it gear. Sounds like the fan is louder than normal too. If you turn it off and start it back up it sounds fine. Thanks in advance.

 

<!--[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]--> CrewCabFan,

Do any warning lights come on? How long does the vehicle sit?

Louis
GM Customer Service

 

No warning lights, and it needs to sits for a couple of hours. Also you don't have to put it in gear, I was going off of my wife's description. When I did it this morning it does the same thing if you leave it in park.

 

check the fan clutch, take off the belt and spin each pulley listen/feel for bearing growls or binding

 

<!--[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]--> CrewCabFan,

"cleveland63b" offers a great suggestion. Another possibility is the A/C compressor trying to move liquid refrigerant through the system. The PCM may need to be reprogrammed with the latest calibration.

This is just a suggestion, not a diagnosis. I encourage you to have the vehicle inspected by a certified technician for an accurate diagnosis.

Please keep us posted.

Louis
GM Customer Service

 

Don't know about posts 3 and 4 but my 2007 Tahoe has dual electric fans with NO fan belts. I believe they are controlled by engine temp and a/c being on.

 

obviously if it has electric fan theres no clutch but theres still a drive belt and pulleys with bearings that go bad

 

Taking it to Chevy in the morning. I'll post back when I hear something.

 

I just had R34 added the other day. If I start the truck with the ac off I don't hear the sound until I turn the ac back on. Could it be too much r34 was added?

 

compressor clutch and/or compressor could be going out