Source of excessive crankcase vacuum on '04 V70 n/a?

[jrschwit]

I'm just getting a newly acquired V70 on the road. There is an occasional distinct squealing sound at idle from the general area between the engine and transmission. Has been impossible to locate precisely. It's not mechanically generated because when I pull the dipstick it immediately stops and there is significant vacuum being drawn into the dipstick tube. Same when I remove the oil filler cap. It takes 5+ lbs of force to remove the filler cap so I estimate at least several psi vacuum. This seems very excessive to me, even for a normally functioning PCV system.

Where and how to pinpoint the problem? I'm guessing a check valve or similar plumbing issue. Any one know of a functional diagram of the PCV and related vacuum hosing for this car?
Jim

[dikidera]

I would reckon the membrane in the PCV has ruptured. Had that happen on my S40 1.6 2003. I had excessive vacuum so much so I couldn't lift the oil cap and would subside as soon as I lift the dipstick.

Replace the PCV(it's under the intake manifold) and all issues should be resolved