BayAreaChevyGuy

Hey guys I have a 2005 Silverado and a 2007 Trailblazer and they both have this sound that can be heard inside the cabin. I can only describe it as a "Slapping" sound. Almost like something in the engine compartment is loose and hitting something. But with the hood up I cannot locate the noise. It seems its only heard inside the cabin. It does this noise at different times but doesn't seem to be triggered by anything.

Its cross model so I have a feeling its something people have experienced before but I cannot locate anything under search.

Idea's....

Thumper_ehhhhh

Well if its not your wife or girlfriend hitting you it could be like mine something in the heat duct.

BayAreaChevyGuy

What in the heat duct could be continuously slapping around like that?

Yuk Yuk.... it wasn't my wife. I checked THAT first.

BayAreaChevyGuy

You may be on to something thoough, it sounds closer to the cabin than the engine compartment..... on both of my vehicles.

Thumper_ehhhhh

I had the same thing in My Astro. Now my Suburban. They sound exactly the same.

BayAreaChevyGuy

Sweet so we've established it happens across the board.... does anyone know what it IS and how to correct it?

Thumper_ehhhhh

pull it apart one peice at a time with the truck running until you find it. Simple solution turn the radio up or open the windows.

OLD WRENCH

Does this only happenwhen you are moving down the road?

BayAreaChevyGuy

Nope it will happen when sitting in the driveway, stopped, driving.

The intensity and interval between slaps stays the same regardless of conditions.

Its REALLY aggrivating and I dont have the know how to take it apart piece by piece.

I would not mind turning up the radio to drown out the noise, I just want to first make sure whatever the noise is isn't hurting anything. Believe me I had a squeeky water pump for 2 months before I fixed it. The radio cured that noise problem too.... but this slapping sound is getting old.

Again, I can really only hear it INSIDE the cabin, when I pop the hook and get up in the engine compartment I can't hear it....

Common Chevy folk, I know someone out there knows what this is. Ive had it in 2 of my chevy vehicles, so I know its gotta be a widespread issue.

OLD WRENCH

Next question,,,does the blower motor speed have any affect on it?