black smoke under boost

[xero]

So I have an 86 944 turbo, it has weltmiester chips and the boost goes up to about 14 or 15 psi (2bar) I have owned the car for a few years and within the last year the car has been idling rough seeming a bit slow to pickup speed off the line and when the boost kicks in at about 3500-4000rpm I can see quite a bit of brownish blackish smoke coming out of the tailpipe, the car also seems to be running low on oil all the time.
the Oxygen sensor has been replaced recently and I even swapped in a different AFM but no change, anyone have any suggestions??

[nize]

1) turbocharger could be blown
2) headgasket could be blown

first thing you should do is a compression and leakdown test. let us know what numbers come up.

[xero]

I did one recently if I remember correctly the numbers were 110-120-120-130 or something like that, I can do another test though
I also changed the head gasket recently and there was a little scoring in the nikasil on one of the cylinders but nothing major

[xero]

oh also, the smell of the exhaust while driving down the street smells very toxic, I know this because a friend of mine was following me in her car and she said she could smell it pretty bad and also once I didn't close my rear hatch all the way and it opened up while I was driving, the smell was very strong, eyes were burning ....but there is no visible smoke when driving normally, just the smell, it's only when the boost really kicks in that the dark brown smoke starts gushing

[AaronM]

I was going to say that they typically do spit out some soot when you got WOT, but it soulds like your problem is more severe.

[xero]

yes it is a large toxic cloud

[AaronM]

Coolant is typically white smoke that smells sweet, so it sounds as though whatever is coming out is not coolant. At least, let's hope it's not coolant.

[xero]

the radiator is filled with water at the moment anyway, no antifreeze
I'm pretty sure that the smoke is unburnt gasoline being that it's dark brown/black, so it seems it's either running very rich or the gas is not being burnt completely for some reason?

[nize]

can you specify exactly how much oil it's going through? one quart every 100miles? 1000 miles?

also, your injectors might be clogged. you can remove them and have them pro cleaned and flow matched for $15/per. read this thread;
http://forums.pelicanparts.com/showthread.php?postid=2481200#post2481200

[xero]

I pulled out my injectors a few weeks ago and blew some acetone through themand replaced the seals, but if my injectors were clogged I think I would be running lean if anything?

The oil consumtion is bad, I do a lot of driving but it's it's probably 2 quarts a week or more.

I was thinking that there may be a bad seal in my turbo that is blowing oil into my intake, but wouldn't that cause white smoke not black??

It would give me an excuse to buy a turbonetics T3/T4 ball bearing turbo at least!

[nize]

'cleaning' your injectors using that backyard method won't work. when they get clogged they don't always run lean, they spray big drops instead of fine mist, so the mixture won't burn completely.

also, the injectors should be flow-matched, which you can't really do on your own without really expensive specialized equipment.

[nize]

to check if your turbo is leaking, you can clean out your intercooler pipes and check after one week to see how much oil is actually ending up in there.

[xero]

Hmmm! I just read a thread on a volvo messageboard and I think this may be the problem?! oil leaking into intake through a blown turbo seal

http://www.volvospeed.com/vs_forum/index.php?showtopic=17147

[xero]

ooo thanks for the tip nize, I'll definatly try that!

I just got my tax return and I must admit I'm kinda looking for an excuse to buy a ball bearing turbo heh

Yes this really would explain most or all of the poor-performance/rough running/bad gas mileage problems i've been having

[nize]

if you read my first post, you'll notice i already mentioned the possibility of a blown turbo.

and i'm nize. nynor is a different guy on here.

[xero]

oops heh sorry about that! NIZE

Oh when you mentioned the blown turbo it didn't really register that you were saying it could be leaking oil, I was just thinking you were saying it wasn't doing it's job (boosting)
anyway, I just got back from taking my mother out for mother's day, I'm going to go pull off my intercooler pipe, clean it out and then do some driving.....though if I remember correctly I think I did notice a there was was more than just a tiny bit of oil in those pipes when I did the head gasket recently!

[nize]

a little oil in the intercooler is normal. a lot is not.

[petah]

had the same problem on mine. It turned out to be a both rubber boots that go from the turbo to the intercooler and from the intercooler to the throttle were split. Under boost, air blows out the splits, leading to less air in the intake manifold that the MAF has led the DME to believe. So, the DME increases the duty cycle of the injectors to provide more fuel to maintain the right mix with all that air. Trouble is, the air isn't there, leading to an over-rich condition and black smoke (lots of it). Both boots are available online, pretty easy fix (you have to take the airbox off, then it becomes easy.

Good luck.

[xero]

would this be the one??
http://www.pelicanparts.com/cgi-bin/smart/imgdsply.cgi?pn=95111037002-M100

[nize]

yeah that's one of them.