I believe I'm correct in thinking this is the crankcase vent.
What has happened over the last year, is more & more oil is seeping out of the vent hole next to the dipstick. With synthetic oil there was a lot, so I'm now back to dino.
I try & keep the oil level at about half way bwt the upper & lower fill marks on the dipstick but still it "oozes".
Do these need maintenance?
How does it come out?