Little Black Debris

[pedrero]

Hi All,

I have little black rock like debris coming out of the heater vents. I bought my 99 Expedition last month and it is running great but i am finding these little rocks on the dash and floor. Is this something serious?

 

[ELVATO]

Pictures? Are they litterally like rocks, or are they like small pieces of plastic/foam?

 

[seeker]

Bits of plastic may be from fan blade breaking down or blade contact with housing. I am thinking it is more likely the foam from the blend doors has gotten brittle and flaking off.