Three updates on the car. Haven't seen it in person but talked to my dad on the phone tonight.

1) The entire underside of the car is soaked with oil, and we know for a fact that when we bought the car, it wasn't like that (rear axle boot replacement job soon after the purchase in August), which implies a recent failure or a new leak that's contributing greatly to the problem. So far we've found a serious leak at the oil pan end of the turbo return line and have got parts on the table waiting to go in to seal that leak up. It's not ALL of the problem but it's part of it.

2) He found a "line going from the turbo to the wastegate" -- that's how I heard the description if I didn't get a scrambled message from that phone call-- that was completely broken in two. Makes us suspect that the car's been running on full unregulated boost unless an auxilary over-boost protection circuit somewhere (something to do with the alda maybe, I've never quite understood that) -- with no signal reaching the wastegate to tell it when to open.

This car DOES have a noticeable turbo spooling noise under acceleration, more than the SDL. He pulled the air tube today and the turbo spins easily and does not wobble or spin out-of-round any. So no wear there. Yet another piece of evidence that the turbo seals aren't likely the source of our problem.

3) The check valve at the foot of the oil separator return seems to not be sealing. Oil flows freely down the tube into the sump -- well not "freely" but it does trickle... however, he put a mityvac on the thing and it wouldn't ever seal. Can suck oil up the tube through the absent-or-damaged check valve.

So... current theory is that in addition to leaking part of the oil out onto the ground, the chassis, everywhere... either excess boost, or normal ring blow-by, or a combination -- MIGHT have pressurized the crankcase enough to blow oil UP through a failed check valve, backwards through the separator, and through the air intake.

So we're addressing all of the above -- whether it's a good theory as to the consumption of oil or not, it needs to be taken care of anyway -- and then will test drive again and see if we've made any headway.

__________________


~Michael S.~
Past cars:

1986 300SDL
1987 300SDL
1982 240D
1982 300SD


Current:

1987 300SDL