One i would check your catch can and two if it is full. empty it. or if it is empty and its been a while since you have emptied it, i would check PCV valve for opperation.
I too own a 6.1 and i too have the filter on the fitting. after working a days work at diablo I leave and go work at my shop in fort lauderdale where I work on Nothing but hemis. that area should not be giving you a wisseling noise and it says there is a blockage somewhere. cause that valve to become a vaccum port instead of just a crank case breather port, is saying something is up.