VolvoDeger;92373 wrotethrottle gasket,, and make sure your sump vent clean otherwise still show as blocked.
Then sump removal required with new seal kit and glue.
I've never once ever ever had to drop the sump to clean it out
Thank said
By doing this work you will drop some carbon flakes into the engine... as such... you should plan to change the oil after doing the PCV and before the car is started again
and then change the oil again after 500k (if the PCV was really really nasty)