I think the turbos started in '81 on wagons, but wouldn't swear to it. Just know mine doesn't have one. I don't have any type oil line, clear or not, going to the air cleaner other than black hose from valve cover over to hole in air cleaner.
Went by an indy today in the same parkinglot as one of my customers(not in my MB), and explained my situation to him. He said it sounded like IP problems. He said it sounded like it was running rich, which wouldn't let it idle correctly, and would cause it to smoke. He said it would run OK at speed, which it seems to do. I asked him about fixing that and he recommended using the car for parts and buying something else. Basically said the cost of the IP work isn't worth it for the car.
What do yall do when you have IP problems? Does his theory sound plausible?
Jimmy

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Jimmy L.
'05 Acura TL 6MT
2001 ML430 My Spare

Gone:
'95 E300 188K "Batmobile" Texas Unfriendly Black
'85 300TD 235K "The Wagon" Texas Friendly White
'80 240D 154K "China" Scar engine installed
'81 300TD 240K "Smash"
'80 240D 230K "The Squash"
'81 240D 293K"Scar" Rear ended harder than Elton John