Today I removed and replaced a cracked hose that went between my air filter housing and the crankcase ventilation pipe. (outlined in green below)

What a chore. It was like a jigsaw puzzle, and I had to insert two parts in at the same time - the hose and the large u-shaped intake line.
It was a total hack job before I got to it today - there was no grommet for the vacuum line from the vacuum pump (outlined in red, above), just a lot of rubber goop I had to remove from both the hole and the hose. The rubber insert inside the u-shaped intake line was shoved to the side and is now misshapen, it does not seat right, but I think I forced it to.
I also discovered all three of my air filter housing rubber mounts were ripped off. I had no idea.
I'll post pics and write up later, if this all sounds greek to you (as it would to me). The great news is that this little hose was spraying oil everywhere, and now it is sealed and tight. But that begs the question - why was oil in it at all? Is there supposed to be? When I took it all apart, oil was actually dripping from the u-shaped intake line. And there was oil in the turbo (but the turbo axle had no play whatsoever! and the blades looked nice and un-chipped! Woo-hoo!) And I put in a new rubber grommet and now the vacuum line seats perfectly.
It's really cool when you have no idea what you're doing and you know if the part doesn't fit your f--ked, but then the part does fit and it all goes back together perfectly.

I just hope the air filter stays in place and doesn't vibrate itself to Timbuktu. It is being held in place by the u-shaped intake line - I tightened the clamps with a socket instead of a screwdriver.