So my idle has been a bit rough lately, so took a look at the throttle body to see if it was maybe hanging up/dirty. Found oil behind the butterfly which i believe is coming from the vacuum line from the throttle body to the pvc valve. Was told this is common in the LS1's and that a lot of people were adding a water air separators to this line to fix the problem.
Any thoughts on this?

 

Very common. You want to fix it permanently? Block off all the ports (1 on each valve cover and the tb port) and run a MightyMouse (board member here) vented catch can.

 

Actually it would be from the PCV valve to the intake is where the oil is coming from. The hose from the valve cover to the TB provides air to the system. PCV valve could be stuck open, you can run a catch can, you could upgrade your valley cover, or you could do what was suggested above. Capping everything off and venting to atmosphere will definetly stop oil in the intake but will give you some level of an oil "smell" from what I have read.

 

LS6 valley cover.......and if your really ****.......a catch can.........i do not recommend eliminating the PCV entirely

 

A GZ Motorsports vacuum pump will keep oil out of your intake/ combustion chambers.

 

^^^Nice but definitely not the cheaper option.

 

Def clean that out, I just did the husky air filter. I put it inline the pcv and intake. I had oil all over the inside of the intake and it was dripping down to my spark plug threads, caused a lot of detonation.

The oil seperator works, but you might want to clean out the intake.