Getting water coming in from under the dash after a strong rain. Any one ever had this problem, if so what was the cause and how did you get fixed.

 

Check out common causes of W-body water leak at Have water leaking into your car? Check here first!!!

 

<!--[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]--> Byron27,

It is difficult to say. It could be HVAC / drain related. This is just a suggestion, not a diagnosis. "EinST" offers a great link with additional possibilities, although they are for Grand Prix, it may apply to your Impala.

I encourage you to have the vehicle inspected by a certified technician for a more accurate diagnosis.

Louis
GM Customer Service

 

Two items for you to look at. The first is the drain plug could have become clogged...there was a TSB about this for model year 2000 #00-01-38-012
Condition:
Some customers may comment that the carpet on the front passenger side is wet.

Cause:
This may be caused by foreign material plugging the evaporator case drain.

Correction:
Inspect the evaporator case drain for plugging.

1) Raise the vehicle on a hoist.
2) Remove the rubber elbow from the evaporator case drain tube by pulling the elbow straight off.
3) Insert a 9 mm (11/32 in) drill bit, or any other similar-type instrument, into the evaporator case drain to clean out the material that is blocking the drain. (The distance to the other side of the evaporator case is 130 mm (5 in)).
4) Re-install the evaporator case drain rubber elbow. A small amount of silicone spray on the inside of the rubber tube will allow it to be slipped into place very easily. Be sure that the rubber elbow drain hole is open.
5) If the evaporator case drain was not plugged, a water leak test will need to be performed using normal water testing procedures.
6) If no external water leak was found and the vehicle returns for the same type concern, the evaporator case will have to be removed from the vehicle and the foreign material removed from the evaporator case.

There was also a TSB regarding the Plenum water deflector either becoming loose or cracked. You may want to search that too.