Chevy Engine TSB, Vented Oil Fill Cap
I came across TSB #PIP3343F: Possible Engine Oil Leak Due To PCV Freeze-Up - (Jan 9, 2018 ). I did some searching and if the PCV system gets clogged it can blow out an engine seal. So as a preventive measure I purchased the recommended vented oil cap. You can see the vent in the middle of the cap. It is AC Delco Part FC219.
Some customers may complain of an oil leak shortly after a cold start when extremely low ambient temperatures are present (approximately below 10*F), or excessive short trip drive cycles.
If an oil leak from the rear main seal is noted, this is the result of a frozen PCV system and excessive crankcase pressure.
If this concern is encountered, clean the area of the oil leak, clean and dry the PCV hoses, and replace the oil fill cap with part number 12589430 (vented oil fill cap) to prevent a reoccurrence