My car had some issues at low rpms with some noise, I wasn't sure what it was. Today I pulled the PCV off and had my engine drink a few cups of water while running. It spewed white smoke for quite a while afterwards and had some misfiring, but that's to be expected of course.
This is me attempting to capture the unhealthy noise on my phone:
http://www.youtube.com/embed/y4pXnLCvMO4
Now that it stopped smoking, I just went for a drive, and the low end power is much better now! No more knocking? noise, much less hesitation when starting from a dead stop, noticable improvement in response at 1000rpm. Gonna see if my mpgs go up. I suspect it was pulling timing due to excessive deposits causing knock.