I know full well my car does not run on diesel fuel. I only put it that way because every now and then, when I may happen to drive like a jackass for a few miles, my car will occasionally treat me (and anyone who happens to be behind me) to a rather large cloud of black smoke (much like my brothers F-250 does).
I am GUESSING that this mean my engine is mixing something other than fuel into its combustion chambers..... Which I assume is probably bad.
I was hoping for insight from anyone who may have experienced this before. Is is oil, coolant, TOO much fuel???

I just wanted to know HOW serious this is before I rush off to a qualified mechanic.

Thanks for any help/guidance,
John

if it matters, my car is a 1999 996 with 85k on the clock.

 

I wonder if the AOS is in need of replacement?

 

Black smoke means oil in the combustion chamber.

 

What's the AOS?

And I kinda figured it was oil. Any idea why it would only sneak into the combustion chamber while I was at very high rpms for prolonged periods or time? Is this a sign that the end is near for my baby?

 

The AOS is the Air Oil Separator. It receives an air/oil mixture from the crankcase (think PVC valve), separates and returns the oil to the sump, with the air being returned to the intake. When the AOS stops separating the oil, it ends up in intake and usually results in a fouled MAF, generating CELs.

 

If is the AOS, it is cheap, not a big deal.

 

Thank you very much for the hope. Any idea how I would go about diagnosing whether or not it was the AOS?

And again, thanks for the help