Mysterious chips found in airbox

[dyerkes]

I am in the process of doing a valve adjustment on a friends 1987 911 Carrera, and found small black colored uniform chips behind the air filter (K&N). At first glance I thought they were mouse droppings, but the air filter box has no openings on the backside of the filter, nor are there any holes on the filter that would allow a mouse to pass thru. The chips are about 3/16th long, cylindrical in shape and about 1/16ths in diameter. I can pulverize them with my fingernail and they seem to be powdery once crushed. Aside from mice droppings, anybody know of another source where these might have come from? The car is in good operating condition, ~130k miles, and has been maintained very well throughout its history. The car purchased a month ago, and had spent its entire life in Texas with the same owner.

Thanks,
David

[Lyle O]

Carbon canister innards? No idea how they would have gotten there, though...You should check to make sure nothing got past the filter. Also, apply a little flame to a sample and see if they burn or melt.

[ossiblue]

Originally Posted by Lyle O

Carbon canister innards? No idea how they would have gotten there, though...You should check to make sure nothing got past the filter. Also, apply a little flame to a sample and see if they burn or melt.

+1 ^^, carbon pellets from the canister.

[techman1]

+2
1995, carbon canister on the 993 is L side, just in front of rear wheel. Came out to the garage one day to a small pile of those same chips!

[Jesse16]

Yep, the infamous carbon chips from your fuel vapor canister. They should stay on the side of the filter where the hose attaches. If on the other side, then your filter isn't seated in the housing properly or something similar. They had to jump the filter somehow.
I took my canister out and jury rigged a little screen on the outlet hoping that helps keep them in. What-ever design feature was keeping them in the canister has obviously failed and it is not easily serviceable. Long as they lay on the bottom its not likely a problem. Air velocity isn't likely enough to suck them up into the inlet.

[dyerkes]

Thanks for all of the responses. Lyle O -I applied flame to the particles, and I got no reaction. The particles are on the backside of the filter, and the hose leading from the canister is located on the backside too (see photo), so it makes sense as to how they got in. I will have to investigate whether replacement canisters are still available and what they cost. Yes, I think the pellets are far too heavy to have gotten sucked into the intake (AFR), so I don't believe there are likely to be downstream issues.

Thanks,
David