resonance tube
 

hello. i am in the process of 'learning' my recently acquired 2000 S. on a tour through my engine bay i noted that everything was really clean except there looked to be a slight accumulation of oil and black soot on my resonance tube, in and around the vacuum valve location. is this normal? thanks, trk.

can you post a picture of it ?

i actually cleaned it all off, so nothing to see at this point ...

It is kind of normal...
 

... because the tubes have mold seams that allow oil to leak out.
A small amount of oil coming from the Air/Oil separator is OK, but if it's excessive then the A/O Separator needs replacing.
Check your throttle body and the inside of the intake plenums for oil.
Happy Boxstering,
Pedro

thanks pedro, my spidey senses were starting to send me the aos direction. no sign of it in the exhaust yet, but i'll give the aos and intake plumbing a look and see what i find. trk.