treimche

I wouldn't say debunking a myth here. Just sharing my personal experience. Even if the seal is flattened and hard, doesn't necessarily mean it leaks. There are other o-rings and gaskets that can leak too. In my particular case, this engine has some funky compression and leak down numbers, so maybe its different on a perfectly healthy engine?

Mr.Matchbox

Have a look at the oil filler cap in this video:

jyeung528

The krank vents blocked flow going into the crankcase entirely, creating a strong vacuum and ring seal and eliminated my oil consumption. However, the stronger vacuum at idle created a clucking sound, which were the rubber seals snapping, probably not a good thing, so I removed the krank vents.

The krank vents allowed air flow to exit the crankcase, which is pretty important during high pressure conditions.

Blocking the breather hose entirely (not allowing pressure to escape) might not be good.

In the case of an additional pcv device in the breather tube, we could restrict airflow going into the crankcase, thereby increasing vacuum, and also allow some airflow out of the crankcase, albeit somewhat restricted.

I'm at 215k miles and feeling lazy. I just top off oil like I've done for the past 15 years and I feel like that's the easier thing to do.