After putting about 3000 miles on my 82 Turbowagon (230K), I have decided that it is using LOTS of oil, about a quart every 500 mi. I never see smoke in the rear view mirror or on startup. It doesn't smell like it's burning oil and it doesn't leak it out. I think I've got lots of blowby because the air ducts into and out of the turbo are prety oily. I cleaned them once and checked a few hundred miles later only to find them oily again. I cleaned the oil separator when I did the wiring harness and there's no factory flame trap in turbos. Also the intake manifold and throttle body were really sooty and dirty before I cleaned them.

How big of a problem is this? can I just buy oil by the case for the next 50K miles and live with it? Any ideas for keeping blowby to a minuimum? Lastly, What part of the engine (top or bottom end) is likely to cause excessive blowby?