Positive Preasure coming from Oil Tank 2016 S60 2.0L Turbocharged, B2404T12

[WMetzger347]

I have been through the Gambit with this car since it hit 150K.
Positive Pressure is coming from the oil separator tank even though I have replaced it, the check valve, and hoses. Even found a the niple back to the intake hosing (from the check valve) was clogged.. and cleared.

Checked compression and had 175-185 PSI dry and withing 20% wet (maybe better).
Wondering if there are ways to verify an engine passage is/is not plugged without causing damage.

Plenty has been done in the last 20k miles. Chasing a miss... got most of it eliminated. But I also did a piston soak, and a Liquid Moly engine flush (twice). Currently, the intake is off cleaning the valves, intake, and throttle body. Found what appears to be small breather holes in the intake... maybe related to (don't know).

I could really use the help... don't necessarily want to button this up, if there are suggestions.

Thanks!

[Vova585]

Sorry for your troubles. Given it is 2.0 with more than 150k, and you did all this work...i would suggest cylinder leak down test. Sorry, dont have anything else