My "new" 1990 740-GL wagon with B230F non-turbo California emission engine is spewing oil from the camshaft seal and maybe elsewhere as well. I have replaced the flame trap, cleaned the Plastic T housing, replaced the vacuum hose, will clear the brass manifold fitting. I believe that the oil separator has never been touched in 179k miles and is probably hopelessly clogged.

I got a green O-ring, a throttle body gasket, and an intake manifold gasket locally. The oil separator is so deeply buried under the intake manifold and is blocked by the EGR, Idle valve and TB from the side. Should I just pull the intake manifold to get good access to the stuff below? I may need to de-carbon the EGR valve anyway, and some have suggested cleaning out both the throttle body and the idle thing at the same time. To get this area really cleaned out, I think it require good, unobstructed access to clean up the area around the separator.

I do have an ultrasonic cleaner that is big enough to hold the oil separator. I was thinking that a few minutes in that with some simple green or some other driveway detergent might be able to get rid of the carbonized gunk inside. Anyone else use ultrasonic methods to clean the "bottle"?

I really don't understand yet how the return hose that goes down inside the engine works. There are warnings about accidentally losing it inside the engine, which would necessitate removing the oil pan. Some say clean it, but be careful, others say don't touch it. If it is the one-piece hose that is shown on the FCP-Groton website exploded view, can it just be replaced?

This will be much more clear once I get it apart, but I don't want to be without a car for a week waiting for parts.

Thanks!