LS3: oil catch can excessive fill-up?!

[TheBrightSide]

Can anyone explain why my oil catch can fills up so quickly? I haven’t had it compression checked or anything, but I know that I might’ve overfilled oil before. Even then, after a while, my dipstick went down even below the max, and the catch can was STILL filling up more than halfway every 200-275 miles or so (depending on how hard I drive; how much I idle, etc.)…

I have a 2010 Chevy Camaro SS, with an LS3; currently sitting at around 34k miles, and I’ve done a pretty decent job at maintenance if you ask me. I haven’t had issues with the factory spark plugs or spark plug wires yet; but recently, one of my primary/upstream O2 sensors went out. The O2 sensor issue shouldn’t be directly related, as I’m sensing that this oil issue might be something deeper, physically going on in the engine block itself.

I recently just did an oil change and still went below the max by maybe half a qt or 3/4 of a qt (usually takes ~8 qts for a normal drain and fill). I drove about 100-150 miles so far, and it’s filled up the oil catch can about a 1/4 way or more. I’m starting to lose some hope….

At first, I was thinking for a second my oil catch can was routed wrong, since it didn’t have any outlet and inlet routings marked. However, if that was the case, I probably wouldn’t be getting any oil in the catch can at all… My other concern is if I reinstall the stock PCV “valve” (more of a “recirculation” kind of valve, between the intake manifold and valve cover), that there must be TONS of blowby going on. Have I been having an underlying issue all this time??

[0stones0]

Search oil valley baffle. Probably has a bad seal.

[morepowerjoe]

Is your engine stock, and what kind of catch can do you have?

[0stones0]

Check this thread. May or may not help.

https://www.camaro5.com/forums/showthread.php?t=621001

[TheBrightSide]

Originally Posted by 0stones0

Check this thread. May or may not help.

https://www.camaro5.com/forums/showthread.php?t=621001

Yeah, checked that thread a while ago, but still can’t tell what it is at this point…. How hard of a job is it to replace the valley baffle seal? I think I saw a video of the process a while ago, but I think you have to get underneath the intake manifold, fuel rails, etc…

[TheBrightSide]

Originally Posted by morepowerjoe

Is your engine stock, and what kind of catch can do you have?

Engine’s stock, as far as I’m concerned. I ended up using a Mishimoto 6th gen Camaro SS (LT1) replica oil catch can. I don’t know about the exact quality of the generic catch can, but the design and everything looks pretty much identical, minus any engravings or logos.

I also just checked to make sure I didn’t overfill or was losing oil right after an oil change. Sure enough, it’s just tons of blowby; literally 70%+ of the catch can was full after a single ~220-250 mile trip… Crazy. I’m basically emptying out the catch can weekly, so that it doesn’t suck bad up oil….

[The_bald_eagle_machine]

That is alot of oil honestly. Is your catch can routed to the intake manifold port for inlet and outlet to the valley cover baffle? Even under boost I only have an ounce or two after 1500 miles or so of hard driving mixed with highway. When my car wasn't boosted, it was maybe 2 ounces between every oil change.

If you have to replace the valley pan gasket. removing the intake manifold is not really that difficult honestly. I had to undo mine to do the fuel rail flip, and it was not difficult. Just use 1/4 inch drive tools so you don't break anything. Torque specs are pretty low.

[TheBrightSide]

Originally Posted by The_bald_eagle_machine

That is alot of oil honestly. Is your catch can routed to the intake manifold port for inlet and outlet to the valley cover baffle? Even under boost I only have an ounce or two after 1500 miles or so of hard driving mixed with highway. When my car wasn't boosted, it was maybe 2 ounces between every oil change.

If you have to replace the valley pan gasket. removing the intake manifold is not really that difficult honestly. I had to undo mine to do the fuel rail flip, and it was not difficult. Just use 1/4 inch drive tools so you don't break anything. Torque specs are pretty low.

So, I can’t recall, but I don’t even which is which on the catch can; although I asked if it would be even be filling up at all if it was routed wrong? It’s identical to the Mishimoto name brand one (6th gen Camaro SS), so maybe I’m assuming the baffling or filter or something inside the catch can, might be a possible issue..?

To check the inlet/outlet on my oil catch can, I can kinda inspect underneath the top, to see the filter element, and then the baffling, right? I forget which goes to which… Also, how else would you be able to tell if the valley cover gasket is bad? I’m kinda confused, cause I tried to look up a diagram and parts, and I keep seeing oil pan stuff..

My only concern now, I guess, is that I want to take off the oil catch can to reinstall the factory recirculation “valve” or whatever (LS3 only). I asked if all the same oil that I caught in my catch can, would be filling up and gunking up my entire intake manifold? I just can’t be emptying out my catch can every single week; this just seems completely pointless… Although it’s not seeming to drop my oil level like crazy at least.

[morepowerjoe]

So do you have aftermarket valve covers, like Holley?