soot stains on interior, common problem?

[JBG3]

so I have a dark coating of diesel soot deposited on the back of my rear seats, most notably the arm rest which apparently never came down.

I thought it was mold, but it smells like diesel exhaust, and can be brushed/shampooed out fairly easy. 

The weird thing is that I can only imagine it coming in from a 2.5 inch round hole designed for a VO system, but the whole trunk was fairly dirty with soot as well.  Is this a common problem? 

Ive been through the trunk after patching that VO line hole, and it seems impossible that it came in through there, but thats the only place I can find that was open to the outside.  The whole rear deck is sooty as well.  Here are some pics-

here you can see the soot on the rear seat-



and once you put the armrest down, its pretty nasty.  Comes right off on your hands and clothes, as if you stood right in front of the tailpipe for extended periods

[R.O.R-2.0]

its soot.. my car has a black back seat, and recaro fronts.. lol.

my back seat used to be light gray, once upon a time..

[TylerDurden]

Any breech of the back trunk area will let in exhaust, if a window is open creating a low pressure zone in the cabin. (More likely if the AC is busted, of course.)

My 89 has a rust hole - I keep the windows up and the fresh-air blower on.

[bajacalal]

Replace your trunk/hatch seal with new weatherstrip and patch that hole.

I've noticed something about these cars. The air flows "the wrong way" if the front windows are open. It flows from the back towards the front. I guess this is due to the Venturi or Bernoulli effect or maybe both. This seems to be more pronounced in the earlier Volkswagen Golf/Jetta than it is in other cars, which have better ventilation, and is the worst when only the front window is open, which draws in exhaust from the rear, if the exhaust can get into the car. Opening a rear window negates the effect.

[745 turbogreasel]

I get soot stains off my clothing sometimes, but that's about it.

[Dakotakid]

Is this electrostatic in nature?

Quick:  someone drag around a chunk of log chain to ground the body and see if this helps!

[JBG3]

Is this electrostatic in nature?

Quick:  someone drag around a chunk of log chain to ground the body and see if this helps!

could you do the same just running a bare steel rim on pavement?   

[JBG3]

Replace your trunk/hatch seal with new weatherstrip and patch that hole.

I've noticed something about these cars. The air flows "the wrong way" if the front windows are open. It flows from the back towards the front. I guess this is due to the Venturi or Bernoulli effect or maybe both. This seems to be more pronounced in the earlier Volkswagen Golf/Jetta than it is in other cars, which have better ventilation, and is the worst when only the front window is open, which draws in exhaust from the rear, if the exhaust can get into the car. Opening a rear window negates the effect.

im definitely going this route, the seats are otherwise reasonably clean, but ive never encountered this level of exhaust grime they apparently filtered.  The rear deck also looks like a used air filter, with soot showing through in every vent position.  My big concern is the amount of soot this indicates alarms me when it comes to me breathing inside the car. 

Im not using the original engine or exhaust though, and the current 85 motor hardly smokes at all, so im not sure what was going on previously the create such interior filth.  I can say the original motor was completely blown though

[bajacalal]

I bet if you were to somehow measure the amount of air that's entering your car in the rear, in cubic feet, you would come up with a pretty big number over 100 miles.

You say you have an aftermarket exhaust. Where does it terminate? If it's before the bumper, a lot of exhaust can be drawn in the cabin, even at highway speed.

[JBG3]

I bet if you were to somehow measure the amount of air that's entering your car in the rear, in cubic feet, you would come up with a pretty big number over 100 miles.

You say you have an aftermarket exhaust. Where does it terminate? If it's before the bumper, a lot of exhaust can be drawn in the cabin, even at highway speed.

sorry, I was unclear, im not using an aftermarket exhaust, I have an 85 stock 1.6 engine, and an 85 stock exhaust I moved over from a donor car.  The original exhaust was a piece of rattling swiss cheese though, and im not familiar with how the original engine ran before the PO destroyed it with abuse. 

I patched the VO line hole, and I definitely need to replace the trunk seal.  For the last 10k I wasn't worried about it, as I had no door seals installed and no interior, and drove with two windows open constantly, but now that I have sealed up the car really well and put in new seals, while at the same time buttoning up all other leaks and holes in the cabin, im getting a little concerned at having closed up the cabin well enough for excellent exhaust retention over the winter. 

yeah, over 100 miles it has to be a lot, or at least more than id like for sure. 

[RabbitJockey]

theres a guy down the street i pay to suck farts out of my car seats, next time i go i'll see if he does soot or if theres anything he recommends.

[JBG3]

theres a guy down the street i pay to suck farts out of my car seats, next time i go i'll see if he does soot or if theres anything he recommends.

Yeah, let me know what he says, talent like that is hard to come by.  However, there's a local topless bar where I could probably have the same services performed on my seats as well provided I have enough singles.

[RabbitJockey]

I tried that before, they did a half decent job of getting the spot out but they left a lot of cheap glitter behind

[wdkingery]

lol the glitter.

well anyway, i'm glad this thread formed, because my exhaust is comprised of mostly large leaks in various places, and it's likely i'm breathing this stuff in! i didn't think about the low pressure/venturi effect!

so i've opened my summer a/c vent and just diffused it.

glad ya'll mentioned this; wifey says i smell like soot every time i get home.. i quit smokin two years ago!

[R.O.R-2.0]

lol the glitter.

well anyway, i'm glad this thread formed, because my exhaust is comprised of mostly large leaks in various places, and it's likely i'm breathing this stuff in! i didn't think about the low pressure/venturi effect!

so i've opened my summer a/c vent and just diffused it.

glad ya'll mentioned this; wifey says i smell like soot every time i get home.. i quit smokin two years ago!

diesel smoke is much more pleasant to smell, than cigs are...

my car has JUST a downpipe, i know where my soot comes from... lol.

kinda makes me want to remove my recaros, and dump them back in the gasser...