Originally Posted by craigsfocus
I wouldn't imagine it would drain back into the engine. Two reasons.
1) Pretty much defeats the purpose of a oil seperator (In a way)
2) The oil it would capture would be milky and contaminated.
If it does drain back in there. This would be an excellent reason to use a high quality oil and filter.
Several of the catch cans I looked at drained back into the engine, they do catch a good amount of crud, from what I remember, about 4 to 6 ounces at 5K to 7.5K miles in turbo applications on good motors. And it was milky with at least three layers (maybe four). Gives one pause, does it not?