Volvo: PCV burning oil, flame trap, coolant temp

Question
I have a 95 Volvo 960. The car runs fine when cold and will do so for several (20) minutes. Then it runs rough and begins to burn oil. I pulled the intake hose off and see that oil is entering through the Flame Trap opening. Why? and what do I need to do. Also it seems to hesitate always at initial throttle but smoothes out right after that. related? something else? The car has 160k+ miles.

Thanks

Answer
John,
I would first check the vacuum nipple (where it gets the vacuum from) for the flame trap and make sure that it is clear. If all is clear and looks good then take a compression test and cylinder leakage test to see if there is too much blow by. That would mean the engine is weak and has worn rings.
Now there is some sign of oil to be expected at the flame trap, but you say that it is excessive. That would indicate worn out rings.
The hesitation may be something else. I can not see what the two have in common. Check the system for codes and see if they leed to something, like fuel trim air mass meter coolant temp sensor.