I wanted to post about this a year ago when I last experienced it. Sounded like I had a bird trapped in my engine bay
Well, this time I stole a brief moment of silence to show off the fault.


The noise was presenting while I had AC running this time. Not always the case.

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The second one shows my releasing pressure built up in the crankcase by pulling the dipstick. Big woosh, and the chirp is gone (until I put it back in, that is)

For those unaware of the goofy blue thing with the red filter that I covered up, it's a secondary PCV valve purposed to create slight negative crankcase pressure. This isn't so much about that, although it is a potential cause for extra pcv issues. It was just a thing for me to check and clean out, an opportunity to see if I could make the noise worse. It's given me some trouble of late. I addressed this fault last time by opening up said added valve and re-flattening the reeds inside of it with some pliers, cleaning the red filter, and replacing the regular pcv valve. The last item there would be the only one of concern for those without said add-on item.

This time I addressed it just by cleaning that red filter.
To do so, I used maf cleaner spray and an air compressor. MAF spray is supposed to be plastics safe, dry quickly and cleanly, and I had it on hand. Air compressor to then blow the filter out and dry any remaining liquid.

Welp, that's all I got! Been a while since I've posted here.. stupid reliable car. It's also got a clutch squeak which I assume is the fault of old fluid (I listened around with the old 1/8" ear hose and the squeak was confirmed at the clutch cylinder). I'll get to it eventually!

P.S. To that dude in GA with the white Fit who shouted "what are the odds?" at me yesterday while pointing at my white sparco terra wheels, I was coming from a work drug test and didn't realize until much later that we had the same wheels, let alone the same car. My apologies for the face I made at you. The odds are shockingly small. Never seen another fit with these wheels

 

From your videos it sounds like the PCV setup is working and is creating a vacuum inside the crankcase. That is pretty neat.. if there is a vacuum inside the block.. then the crank and pistons are not having to fight against any air that is inside.

 

That's the idea! You know though, I never checked to see if the discovered woosh was one of pressure vs. suction. I just assumed it was built up pressure, totally ignoring the concept/purpose of the thingy I'd installed. I'll check it out!

 

I would think if it was pressure that the dip stick would be popping out.. see if you can hook up a pressure / vacuum gauge to the dip stick tube and confirm it.