Luckymba

Strange one for you. It dropped to 50 something in Florida couple weeks back and as I was using the defrost for the first time in 2 years it cranked all the way up and quite a bit of black foam shot out of the vents and all over me and the car. Like soot from a chimney. There were some bigger pieces about the size of a quarter and I picked them up and it looked like black/gray foam. It was a bit sticky almost like it was down the path of decomposition. Yesterday I ran the AC on high and switched between the 3 vent locations for a couple of minutes to clear it and it shot out again of each location. In the center I noticed some pieces about the half the size of a post-it note behind the grates so I got some tweezers and picked them out. It is strange stuff. Looks like foam but if you squeeze it between your fingers it turns sticky, gummy and doesn't bounce back. I removed the old cabin air filter and it looks fine - I expected to see it shredded to pieces. Just ordered a new cabin air filter and will install shortly but any thoughts on what it could be?

GSIRM3

Could it be some type of mold that grew in your HVAC system with all the humid air you get down there?

fskof

Check your pollen filter. Did a mouse decide to build a nest in your vents?

Luckymba

So I pulled out the cabin air filter and it looked great (is that the same as the pollen filter?). And the foam is definitely man made. Really the strangest stuff. The pieces were a uniform thickness - about 1/10 of an inch thick and of various sizes and are gray/black in color. I really did think my cabin air filter got sucked down somewhere into the porsche mulcher and kicked out the vents. When I pulled out the cabin air filter it was made of a different material. All the stuff that came out seemed to be foam - from little pieces that dotted my arms like freckles to the big pieces about 1/2 post it note or quarter size that made it through the vents.

Carrera997re

Maybe the insulation in the vents the foamy stuff broke up in time from the humidity and pooof blew out.

awrryan

I know what this must be and had the same thing happen in my 996. I think it's the foam from the flap inside the dash that opens and closes to send hot or cold air to the vents depending on the selected temperature. Mine deteriorated in my 996 significantly but I never noticed a change in temperature inside the cabin.

Captsteve123

That foam is like weatherproofing, for the outside air intake flap, to help seal it when it closes. Sometimes, you will see this foam come apart from age. It also helps seal and vent connections. No big deal!

slicky rick

Anybody have a diy on best replacement procedure? Capt is right and it happens usually with age.

Luckymba

I like the "no big deal part". Thanks guys for all the info.

USMC_DS1

Here's the cabin air filter change DIY for reference JIC: https://rennlist.com/forums/997-foru...l#post10348842

CORSASCHNELL

It sounds like a normal part decomposed into a foam like as you describe it. I would take the stuff to a Porsche dealership and see what they say, if you saved some of the black foam.

Cloudspin

My 996 did it as well. I got a lot of it over a two year period of South Florida driving primarily in A/C mode - enough to make me believe the material was used for more than the OA intake flap. Dealer and two indy's said "they all do it" and just get used to it. It was a pain with clients in the car asking what is this stuff blowing out of the vents? Hopefully PCNA has a fix for our 997s.

shammerman

Had the same in my 1999 Boxster...

Captsteve123

This happens to most old cars, not just Porsche. I believe it deteriorates quicker that any other types of seals because your AC in your car changes from ice cold to hear mode, and that product does not hold up well after years. I just don't think that material holds up well.

dherrick

My 2003 996TT has the same issue. The problem is the foam lining has deteriorated on the flap door that distributes the air from the A/C or heater. The problem is for some unknown reason Porsche decided to use a foam covered metal door panel that has large holes in it beneath the foam. Presumable to save weight but who knows. So once all the foam is gone, the door doesn't work very well with large holes in it.

The rigorous method is to remove the dash and the A/C unit and recover the doors with duct tape or weather stripping foam. However, there is a DIY on the Renntech forum showing a repair that is mostly accessible from the trunk area. You need to remove the heater core but then you can access the offending door. In case the link doesn't go through you can find it in the 986 DIY under - Fixed my lack of heat problem. In the DIY you'll see pics of the "Swiss cheese" naked door panel.

http://www.renntech.org/forums/topic...the-procedure/