I had a look at my service manual; and I found this passage describing how the PCV system works on the LXV/LDE/LLU/2H0 engines.
From what it describes in the Incorrect Operation table, it looks like the calibrated orifice in my valve cover is leaking. And I can kiss $165 goodbye; because NOBODY but GM has that valve cover!
Sent from my iPhone using Tapatalk