I think this is the correct board for this issue:
I have my car in storage in a carport outdoors. No water gets to the, car but it can get very humid at times. It is in the northeast, so the temperature is pretty cold around now. I go to start my car up after a few weeks of sitting. It starts fine, after cleaning some acorns out of the engine bay(damn critters) Anyways so the engine is running, i put the heat on, and i start to cycle through the settings from vent, to heater, to defroster. When I put it on heater, i put my hand in front to make sure air is comming out of the vents, and all of this black stuff shoots out onto my hand and continues to shoot out onto the carpet for a while. I thought it was dirt, but had no idea where it would have come from. Upon closer examination, it turned out to be sticky, black pieces of foam. It didn't come out of the vents, and a little came out of the defroster. But a ton came out of the heater and covered the carpet. My questions: where did it come from, what needs to be replaced, if anything? How hard is it to do? what would cause this? and has it happened to anyone else here?

My car is a 91 firebird 305 5 speed tpi with AC.

Thanks for your help.

 

what it is, is in fact foam padding and insulation from around the ducts in your dash vents. Over time it starts to get old and rot. When I had my dash off recently, I took and replaced all the foam pieces in my vents. Easy job, just take some foam rubber, cut it size and glue it back in place. I also did this with the foam around the air vents so they wouldn't droop.

The Trickster!!!!!!!!!!!!!!!

 

My car was in storage for near past 5 years, since about 96. When I fired up the heater after not using it for 5 years it was fine, it is an 87 that I have owned since 92ish.

 

It must have been the extreme humidity that rotted the insides out. The individual pieces were very damp. Is that something I should ideally replace or can i let it go, especially if it is a summer car. What purpose did it serve origionally. Why not just have the plastic ducts?

 

The foam helped seal the duct to the next duct or outlet, whatever the case may be. I suppose it would also help prevent rattles. Without it you would have less flow from the outlets and your heater, or defrost, or A/C wouldn't work as well.

 

It's more likely been the foam used on the control doors inside the underdash heater ducting. After a few years that stuff will fall off if it's touched, like the foam used on the headliner panels.
The foam that is used to seal the ducts is more like a sponge or weatherstripping foam, and would tend to be blown outward from where it was placed, rather than into the ductwork and out the vents.

Pete

 

I know that there were squirrels around the car, they stored a few nuts under the cover, and a few on the engine
Is there a possibility that they could have gotten into the ducts and knocked the foam loose? If so, what do I need to tape up to prevent them from getting in? where is it located?
Thanks

 

Nope, it wasn't the squirrels that did the dirty deed.

The Trickster!!!!!!!!!!