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I’ve looked around and haven’t quite seen the same issue, or maybe it’s the same issue but presents itself differently?
I took a 5.3 out of a Tahoe that I knew to be in good running condition, no smoke or issues at all. Did a mild cam and springs, then swapped it into an E46 convertible with a Vortech V3 supercharger on a Holley Terminator X ECU and T56 Magnum F trans.
After dialing in the idle and checking for (and fixing) leaks at operating temps, I took it for a short drive around the block, in 1st gear, sub-2000 RPM, and not entering into positive boost pressure.
I didn’t have anything connected to my passenger side valve cover vent and oil had come out from it, making quite a mess. The driver side PCV at the rear of the valve cover was going to the intake manifold after the TB.
I decided to cap off the intake manifold where the PCV was plumbed into, connect it to the passenger side vent via a T-fitting with the single line going to a catch can, which simply vented out the top. I figured that would at least be “okay” enough to go around the block another time.
Well, the catch can filled up with oil and now I’m left scratching my head.
My initial thought is that I just have too much oil in it, it’s an aftermarket oil pan so I’m trying to figure out where it should be on the dipstick, unless that doesn’t change? The car seems to run just fine at least in the 15 mph range in 1st gear.
Does your throttle body have a hose port? If so then run a catch can between the passnger valve cover and the throttle body. Keep the hose from the intake port to the driver side valve cover. Can you post a picture of the PCV line connection at the back of the driver side valve cover? Curios if the valve cover has a 3/8 stem to connect a rubber hose or is it something else?
Does your throttle body have a hose port? If so then run a catch can between the passnger valve cover and the throttle body. Keep the hose from the intake port to the driver side valve cover. Can you post a picture of the PCV line connection at the back of the driver side valve cover? Curios if the valve cover has a 3/8 stem to connect a rubber hose or is it something else?
Yes the throttle body has a hose port as well, I blocked it off because I thought getting boost pressure in there would be bad. I can get a picture after work today but the rear driver side PCV has a rubber grommet that the PCV valve with the hose barb goes into.
I checked compression last night and it was all 170 +/- 10%.
The next thing I'll check tonight is my oil level since there is a good chance I overfilled it, but I had issues with the dipstick port on the E46 LS oil pan, so I just capped it off. Now I have to get under the car, remove the cap, and check the oil that way.
It's just odd that with decent compression and not having even been into positive boost pressure yet that it would fill my catch can in about a 1/8 mile drive at 2k RPM. I have a friend bringing by a better baffled valve cover because the Gen III passenger side (the one blowing oil) has really poor baffling.
Last edited by TBS1775; Jul 20, 2023 at 08:11 AM.
Reason: Typo
Okay so you have the Gen III style valve covers where the driver side has to use a PCV valve. On my LS1 covers there was no PCV valve in the grommet and it was located in the line right before going into the intake manifold. Swapping to the newer style valve covers would be better for sure.
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PCV, oil puking, and catch can question 
