Soot...is this normal?
 

I let my turbo 240 warm up while I was wiping off the windows this morning. The car had been idling about 5 minuets when I got to the rear window and noticed a fair size ring of soot around the downturned tip of my exhaust. I recently turned up the ALDA, but I don't get much smoke when accelerating. The engine runs great and has not used a drop of oil in the 1000 or so miles that I have driven it. What’s the deal?

Soot is 100% normal. Even if you tune it to the point where you see no hint of black smoke out the exhaust, there will still be soot.

The only way to remove 100% of the soot is to install a particulate trap.

OK. Just wanted to make sure. I've never seen such a large pile of it. :D The gutter still has a lot of black in it and you can see a stripe along the road from where I accelerated away from the curb. :eek:

even my moms 05 passat TDI leaves soot marks on the ground and blames it on my old diesels!

But some 505 degreaser gets the stuff off the floor.

Here is a picture of about 1/3 of the soot I left at the curb this morning. :cool:

i really need to replace my alda and make sure the switchover valve thing works..

Humm, that does not look right. That's some thick soot. Have you just been sitting on one spot and revving it all day? :D

Hmmm. Yes that does not look right either but looks like something I have seen but unfortunelty I can not find the picture right now. On my 76 300D when the muffler fell off I shook it out and I would say 2-3 cups of soot (exactly like pictured in your picture) came out. And that was just after I stopped shaking it out.

So If there was ginormous amounts stored up in there I could see if there was some pressure through the exhaust it would dump it out.

bg.... your running a straight pipe? correct? perhaps thats why

I did a stationary italian tuneup (rev to 5k in P) one day after a lot of city driving and it put out a thick black cloud and blew soot on the ground from under the tailpipe to about 8 feet back. Wasn't very much at all...I couldn't even get much of it to get on my finger when I touched it. After "clearing its throat" twice the exhaust was nice and clean.

Mine did the same thing while doing an Italian tune-up on a nice long slope near my house. I just happened to look back and there was a huge cloud! That's only the second time I've seen it do that. I think I'd be concerned if it left soot like that on a regular basis.

Yes, I am running a brand new straight pipe. The down-pipe is used however. This was the first time I had started it after a 6 hour 70+ MPH run (with lots of hills). The car was just idling when it happened. I looked at the tail pipe after it had warmed up and there was no soot being produced at all. :confused:

is the engine temp getting to the normal range? i have seen many diesels with soot problems, that weren't getting up to temp

I think that the thermostat is stuck open because it warms up very slowly. Once out on the highway it stays at 175 degrees or so.

I just went and gave it another cold start. No soot pile this time...until I revved it, then I got a bit of a black spot out of it. I think it must be collecting in a low spot in the straight pipe. I don’t see how the larger bits could make it through the turbo intact. I turned back my ALDA a bit, we'll see if that makes a difference.

I might as well suggest the obvious...
You noticed the soot after turning up the fuel, you might want to replace the setting to where it was and see if the soot is reduced before looking at other possible causes.