I seem to be getting quite a bit of fuel vapor whisping from my catch can and oil fill after driving hard and coming to an idle. I don't recall seeing it before but I cannot say for certain how old the issue is. There's a fair bit of blowby coming from the oil fill as well.
However I couldn't see any coming out of the oil dipstick and I've never had a problem with it popping out.
I did a compression test and cylinder 3 was lower than the rest, I figured the rings may have about had it even though there is never any smoke out of my exhaust and I don't use oil but when I pressurized the cylinder at tdc on a lukewarm engine I didn't get any noticeable pressure from the crankcase. I did get a little noise coming from the tailpipe though. Probably unrelated but I started getting a P340 code today, replaced the camshaft position sensor and it went away for a couple of hours then popped up again.

So as for recent history the car was down for a few weeks while I did various things including installing a ix turbo and completely deleting the egr and evaporation parts, did not mess with timing. Could something weird have happened here? No problems with afr or running, boost leak tested to 30psi. Could valve stem seals cause this? Sounds unlikely but if it's something I can fix I'd rather just fix it- if it's full rebuild time I'm going to simply run the thing until it doesn't run anymore

 

Just wanted to add that my timing is correct as well.
Which is bittersweet because that would have tied everything together nicely.

 

What are the compression readings?

 

165, 163, 145, 172

 

Did you take those readings warm?

 

Lukewarm I'd say. The car was sitting around for half a hour or so after being driven.

 

Once I got it retuned it cleared up a lot. I guess it just spooked me because I didn't expect so much from just running a little rich.
P0340 disappeared once I cleaned off the battery and engine grounds

And I did another compression test and this time cylinder 3 was at 165psi... Not sure what's going on with that because I tested the bad cylinder and a good cylinder twice to confirm it the first time around.

 

Well you did say it was luke warm. It might have been up to temp this time around? I know I'll get a bit of a smell on some pulls, but that is just the reality of having a vent to atmosphere catch can.