I have an oil leak at the rear of the oil pan of my Gen 3 LS6. If the car sits and idles I get no leaks. If I drive it and return then it pools under the car after turning it off. I checked and its not the rear main seal, I replaced the cam sensor and o-ting with a factory sensor, its not the oil pressure sensor and I also pulled and replaced my oil pan and gasket and verified the rear is level with the bellhousing.

This leads me to wonder if maybe my vacuum lines are routed wrong and causing pressure to build in the engine and forcing oil out.

I have them run as shown in the picture below.

RED CIRCLES - capped off
YELLOW- rear driver side to throttle body
GREEN- valley fitting under throttle body to catch can, catch can to passenger valve cover.

 

Drivers side will work, the passenger side is completely messed up.

You need metered air coming into the engine to where it can pull the crankcase pressure. Plenty of diagrams out there on it. At the moment you don't have that.

This is how it should be.

 

I swapped things around. I also capped the drivers side because I saw a few posts that said to do so on the LS6.

 

Mine isn't but I guess you'll figure it out.

 

Yeah, you need the fresh air signal from the intake tract else you will have a **** load of crankcase pressure. I made this mistake years ago and the car sounded like it had a procharger on it lol ... Could pull the oil cap off, run it and it would be fine. Soon as you put the cap on or your hand over the fill port, it would struggle to stay alive.

 

If you're running a sealed can you need to connect it to a vacuum source. You cannot just run 3/8 hose off each valve cover to sealed can like you are showing and also cap off the intake and throttle body ports. By doing this you are not relieving the pressure in the crankcase and you risk blowing seals or blowing the dipstick out of the block.

 

Aren’t the two red circles above a vacuum source? Im wondering if that’s where my leak is coming from. Am I running too much pressure and its blowing oil out

 

This is the one I am using and it says its a baffled catch can. Wouldnt the little cap that I circled on top be a pressure relief?

 

The line on the Throttle Body is the air in, as I explained it. It wont work unless it's a loop. Several of us explained it above.

Throttle Body air in, the port on the Intake Manifold behind it is the vac port. There's the loop just set it up right in between them two.

 

I understand that but I am utilizing an oil catch can. I know most people say you dont need one on an LS6 but I am using one and mine does loop from the valley cover port to the intake manifold port. So it should be correct just with a catch can instead of the loop.

like this:

 

The only real vacuum source is the one on the intake manifold with the throttle body having some but not much. If you want PCV then I'd connect the out on the can to the intake port and then run the hose off the passenger valve cover to the throttle body port. I don't like PCV so I vent my valve covers to a oil catch can that has a breather on top a/k/a breather can but 3/8" hoses are not really big enough and 8AN lines may be enough but 10AN or 12AN is better. Do it that way and you can cap off the throttle body and intake manifold ports as you have shown and still be able to relieve the crankcase pressure and not have the intake manifold pull in moisture and spent gases from blowby back into your engine. My .02

 

When I say the term "loop", it's not the physical shape of a damn hose. It's the system as a whole. Air IN off the Throttle Body to the Engine Crank Case, and eventally the Vac Port at the end of it so Crank Case Pressure can be sucked out of the Engine. There's the "loop" of the process.

Set it up like that diagram. My edited picture of yours above showed the same thing but clearly I wasted time in drawing it and posting it since you needed to find a diagram, that said the same...