We had mice under the intake. there is quite a large flat mouse motel area under there.
Then you have VVT giving up the ghost and cam tensioners sticking.
All this seems to happen with a dry start after an oil change.
Of course These top filter are ALWAYS EMPTY in a couple minutes after shutdown.
It could be timing chain racket. Happens all the time. - except on small Honda 4 bangers.
I gotta disagree with you here, ARCO!
My daughter complained that her Impreza was hard to start after sitting all day at school just after my wife got it a cheap oil change where they used a filter with no ADBV....I put a Subie blue can or WIX 57055 (can't remember which) in it and no more complaints.
When I do a change on my FXT, a lot of oil still comes out of my filter after I drain the pan....I'd guess it's usually about 10 minutes between pulling the plug and taking the filter off.
I think the ADBV maintains a column of oil for a long time even with the top mounted filter.
IDK, maybe some weird gravitational effect from you being further North than me and closer to the mountains in NH?