What's in my airbox

dram · dram's Garage

I am doing a little maintainence on the Porsche this weekend. I noticed some small black pelets in the bottom of the airbox. Any ideas?

Early_S_Man · 03-29-2003, 11:21 AM

Are those holes drilled in the top of the airbox? That could be your answer ... IPO! AKA -- Idiot Previous Owner ...

dram · dram's Garage

No holes. The stuff is not plastic. It is heavier, like graphite or something. It seems like it is there for a reason, but I can't imagine what it would be.

masraum · 03-29-2003, 11:48 AM

could those be animal related?? waste?

tryan · 03-29-2003, 11:53 AM

texan mouse droppings? taste one ( just kidding , that stupid 78 garage targa tasting the acidic oil cracked me up )

grab a handfull and post a close up.

dram · dram's Garage

I wondered why it looked like something had been nibbling on the air filter.

Nope. It is definitely not animal related. Here is another pic.

Thanks.

bell · bell's Garage

had the same thing in mine when i first bought it, it seemed to be related to the aftermarket filter (the glue resin stuff that seals the filter material to the rubber gasket)
i switched to an oem porsche filter and haven't noticed any of that since.
take a GOOD look at the filter that was in there........

tryan · 03-29-2003, 12:14 PM

i have had mice eat into unopened boxes of poison and make secret stashes in the cars. at moms house, we thought the 15# dog was eating 50# a week untill we looked in the boots in the closet next to the bowl.

shop vac that stuff out. if they did not eat through the air filter, i would not worry. we now have IPR. idiot previous rodents. must be french.

APKhaos · 03-29-2003, 03:26 PM

Dram,
That, my friend, is charcoal that has migrated from the charcoal canister tucked up high in the front of the pass rear wheel well. It is part of the dread emissions control system. These little buggers are DANGEROUS. Get a few past your air filter into the engine and they cause baaad things to happen. They must go!

Carefully vacuum them out of your airbox. If you think it is possible that a few might have snuk past the filter while you were poking around, pull the rubber boot off the throttle body and vacuum the little devils out of there too.

Next thing to do is disconnect the line from the canister to your airbox. OK, its not the greenest thing you'll ever do, but do it. Tuck the line away and let it vent to atmosphere.

DO all this before starting your engine again. Did I mention that they will hurt your engine if they are ingested?

tryan · 03-29-2003, 03:53 PM

ahh the ole charcoal pellets trick. do the hoses allow injestion past the air filter? are replacement canisters available?

APKhaos · 04:22 PM

Quote:

do the hoses allow injestion past the air filter?

They are already downstream of the airfilter. The airfilter is clamped between the edge of the airbox and the cover. Now, they have to be lifted from the floor of the box up to the inlet duct. Feeling lucky?

Everything downstream of the airfilter is optimised for high volume airflow. First time you go WOT, any pellets that make it to the duct get a 350CFM rocket ride straight into the top of your engine. Definitely baad boogie.

Replacement canisters are available from PCNA spares.

tryan · 03-29-2003, 04:20 PM

the charcoal canister on the 914 is plumbed to the engine side of the air filter. the canister is fine ,but the rubber line is delaminating internaly. the rocker panel has to be removed to replace the line. i have a cotton ball and a screen in the line now, because the cars are stored in the basement/garage. ( no fumes allowed )

dram · dram's Garage

Thanks for the info. I have vacumed everything out good. I will goahead and disconnect the hose. This definitely looks like trouble waiting to happen.

Don

SK · 03-29-2003, 05:51 PM

I found the same thing in mine the other day. Looks like I will be diconnecting the hose as well. Will everything run ok w/o this hose plugged in?

APKhaos · 03-29-2003, 05:57 PM

OK, if you are going to disconnect the cannister hose......

- report yourself to your local EPA office
- block off the barb in the airbox. Don't want unfiltered air coming in there.
- drive happy

SK · 03-30-2003, 05:08 PM

Ok. This is how I solved the problem. Opened up the airbox and cleaned it out. Diconnencted the oultet hose from the Charcoal can and sucked it clean with the shop vac. Went to the local ato part store and bought a "performance fuel filter". Intalled it right after the outlet flance of the charcoal can. Now, if charcoal burps out again, it will be stopped by the filter, and I can see it. The smog police will still be happy. (see before and after pics.) Total cost $10.

Gordo2 · Gordo2's Garage

I haven't opened the air box but have a bunch of the stuff around my engine compartment.

Odd that this topic came up today. I just mentioned it to my wife the other day.

Gordo

Wil Ferch · 03-31-2003, 07:35 AM

Would like to go back to early_S_man's comment....look at the original photo...
Are there holes drilled on the *downstream* side of the airbox...topside ?? Holy smokes! ...it looks like it's drilled.

--Wil Ferch

Rot 911 · 03-31-2003, 07:42 AM

Quote:

Originally posted by Wil Ferch
Would like to go back to early_S_man's comment....look at the original photo...
Are there holes drilled on the *downstream* side of the airbox...topside ?? Holy smokes! ...it looks like it's drilled.

--Wil Ferch

I would have to go out and look at my airbox to be sure, but as I recall that is just webbing cast into the plastic to give it more structural strength. Look again at the pic. Those "holes" look awfully square.

APKhaos · 07:46 AM

Nice solution, SK. Thats a good way to keep the original cannister and prevent any further charcoal pellets being drawn into the airbox.

Will, Mark: This is not a drilling issue - they are charcoal pellets delivered with the car. Just not staying where they should be!!

What you are seeing in the top pic are the square webs in the casting which is the top of the AFM - behind the airbox.