vacuum gauge to solve idle issue

Oil can get blown up past the bushings and end up in the bottom of the housing. There is a drain hole there for it to escape. This is a natural oiling system. The mechanism that brings the oil up there is called blow-by, or crankcase pressure. The PCV is supposed to minimize this pressure but as the rings wear out, the minimizing gets less and less. I have seen engines puffing so hard the dipstick wouldn't stay down. A little oil in the bushings is a good thing. Unless the bushings are so worn that the reluctor gap will not stay constant.