I should give you more insight: after I got the 9-5, a weird whine started to appear when the car was cold, I suspected it was the sludge. Took it to a shop, to have the pan dropped and cleaned, they did that and also replaced all of the crank bearing, as they were worn. So clearly, the car at some point, had some issues with the oil. That's why I'm looking into the PCV update.
Side question. The car has some weird hissing noise, coming from the passage side of the engine, could that noise be generated by a worn idle pully?