LS3: oil catch can excessive fill-up?!

[TheBrightSide]

Originally Posted by morepowerjoe

That's why I was telling you to check your oil cap for pressure to know if you have blow by from your rings.

I didn’t feel anything blowing out of the oil filler cap area. I can double check, once I get my car running again tonight or tomorrow. I assumed that my engine valley cover and gasket for it, were okay and still somewhat “new”, so I didn’t bother to take my intake manifold, harness, coil packs, and fuel rail off, to check.

How else would I be getting oil blow-by, if nothing so far indicates like a solid cause..? My oil level also isn’t dropping like crazy, as I mentioned; although I guess a month with moderate to hard driving like once a week or few times a week, would probably need at least half a quart or more to top off within a month.

Does the PCV system under the LS3 engine valley cover, have malfunctions, that can cause blow-by, similar to the way the early 2010 L99 and other GM V8 engines (with DOD/AFM), had faulty drive side valve covers (which allowed the PCV to let oil blow-by occur).

[morepowerjoe]

Originally Posted by TheBrightSide

I didn’t feel anything blowing out of the oil filler cap area. I can double check, once I get my car running again tonight or tomorrow. I assumed that my engine valley cover and gasket for it, were okay and still somewhat “new”, so I didn’t bother to take my intake manifold, harness, coil packs, and fuel rail off, to check.

How else would I be getting oil blow-by, if nothing so far indicates like a solid cause..? My oil level also isn’t dropping like crazy, as I mentioned; although I guess a month with moderate to hard driving like once a week or few times a week, would probably need at least half a quart or more to top off within a month.

Does the PCV system under the LS3 engine valley cover, have malfunctions, that can cause blow-by, similar to the way the early 2010 L99 and other GM V8 engines (with DOD/AFM), had faulty drive side valve covers (which allowed the PCV to let oil blow-by occur).

I think your next step would be a compression test.

[morepowerjoe]

I believe what you could be experiencing is sticking piston rings. The reason I say this is because you only have 34k miles on your engine, so I think it's safe to say that your engine has been sitting around for a while. That and I'm not sure but I willing to bet you haven't changed your oil enough in the past either because you or previous owner thought it only has X amount of miles so it doesn't need to be changed. It needs to be changed at least yearly. I also don't think that there is anything wrong with your pcv stuff under the intake allowing more oil to accumulate in catch can, if anything I could see it being gunked up allowing less oil to get by it. So that only leaves one thing, your piston rings. There are a few successful people out there that have used a mechanic in a bottle to unstick rings but most are not successful in their attempts. A general compression test will tell you weather or not that is your problem. Sorry sir I'm sure this is not what your wanting to hear. You can google "low mileage engines with stuck rings" and read about it if you want.

[0stones0]

Give this a read…
Excessive oil in catch can remedy

[TheBrightSide]

Originally Posted by morepowerjoe

I believe what you could be experiencing is sticking piston rings. The reason I say this is because you only have 34k miles on your engine, so I think it's safe to say that your engine has been sitting around for a while. That and I'm not sure but I willing to bet you haven't changed your oil enough in the past either because you or previous owner thought it only has X amount of miles so it doesn't need to be changed. It needs to be changed at least yearly. I also don't think that there is anything wrong with your pcv stuff under the intake allowing more oil to accumulate in catch can, if anything I could see it being gunked up allowing less oil to get by it. So that only leaves one thing, your piston rings. There are a few successful people out there that have used a mechanic in a bottle to unstick rings but most are not successful in their attempts. A general compression test will tell you weather or not that is your problem. Sorry sir I'm sure this is not what your wanting to hear. You can google "low mileage engines with stuck rings" and read about it if you want.

It may have possibly been the original owner(s). I got the car around 18k miles and have been changing the oil roughly every 5-6k miles or so. Not that the kind of motor oil I use could possibly cause any damage to the engine, but I usually use any of the Dexos emissions specific rated 0w-30 or 0w-40. If not, I usually run any Dexros or Euro spec 5w-30 or 5w-40, without issues.

And as I figured from the start, I’m definitely gonna get it compression tested eventually… For now, I’ll leave the catch can setup as is. I don’t think that putting back the “u”-shaped valve, is going to do my engine any favors, as it absolutely DUMPS oil into the intake manifold….

I wasn’t fully aware of sticking piston rings, but I see a lot of people taking out their spark plugs and then filling up the cylinders with ATF, Seafoam, Marvel’s Mystery Oil, or some sort of engine treatment/cleaner. And as far as oil “additives”, I’ve definitely tried my fair share, but I don’t think I’ve used enough, or at least added them to the cylinders (via the spark plug tubes). Some people even say to just beat the snot out of the engine, as a last resort (or first resort) method LOL (I think most of us probably have given it the “beans” at some point).

I do rarely drive this car hard, and I baby it most of the time on a daily basis. Even when I do drive “spirited”, it’s not more than like 2-4 WOT straightaway runs, back-to-back; or I’m out doing donuts and sliding my car around, usually in 2nd gear or 1st gear and not generally bouncing off of the rev limiter constantly.

[gtstorey]

I wouldn't add anything to the cylinders based upon a guess of stuck piston rings. I will be surprised if that is the problem. If the 2000 mile per year is anything like spread out, I don't think that is the problem. If that was 20k miles in the first year and then set for 10 years, maybe.

[TheBrightSide]

Originally Posted by gtstorey

I wouldn't add anything to the cylinders based upon a guess of stuck piston rings. I will be surprised if that is the problem. If the 2000 mile per year is anything like spread out, I don't think that is the problem. If that was 20k miles in the first year and then set for 10 years, maybe.

I didn't think adding anything to the crankcase would probably help either, huh...like as far as the cleaning-style engine treatment formulas (ex: Seafoam)? People were saying to use either those, or something more of a solvent-based, like Berryman's B12 Chemtool or B60 high mileage, for a top-down piston soak.

I did read that the solvent-based cleaners were to NOT be added through the engine crankcase, which makes sense. I've never ran any cleaners through the engine, except for the top engine/intake system and valve cleaner, which I sprayed into the intake via the intake hose. Aside from that, I've added some Marvel's Mystery Oil to the engine crankcase, but not much, maybe a few small ounces or so.

At this point, I can probably just keep driving and check the oil catch can. As confused as I might be, with no instructions or manual listing the inlet/outlets on the oil catch can (knockoff Mishimoto catch can for 6th gen Camaro V8); I think I have the catch can routed properly... I just don't want to put back the "u" shaped factory valve, nor do I want to take out the in-line PCV/check valve that I currently have (in the supposed "inlet" port routing).

[TheBrightSide]

Originally Posted by morepowerjoe

I'm guessing that you've never seen the bottom of your valley cover correct? The reason I know this is because you should have a pcv system under it.
https://www.carparts.com/details/Che...ll%20-%20Parts

So, idk if I was confused initially or after, but I guess I stick with my original research. What you showed me, is the equivalent of GM P/N 12570471, which is an identical engine valley cover to the one on my LS3 (GM P/N 12599296), except the baffling system underneath the cover, is for AFM/DOD-equipped GM V8 engines.

The LS3 engines don’t have a PCV system like the L99, as far as I’m concerned, which makes use of small orifices in the breather ports (to slow down blow-by). For the Ls3, it simply “recirculates” the outlet (engine valley cover port) to the inlet (intake manifold port), with a “U”-shaped quick-connect valve (GM P/N 12599298), which they identify as a “PCV” (older example, GM P/N 12594779)….

I guess both the LS3 and L99, and other GM V8 engines have part of the PCV system, on the passenger side valve cover. This is where the 90-degree breather port, has a connection routed to the air intake hose. Is the passenger side valve cover port supposed to intake metered air? I remember leaving the valve open or with a breather filter; and both would cause a lean engine condition. Once I either blocked off the passenger side breather port, or connected it to the intake hose, it would resolve the lean CEL code…

[TheBrightSide]

I ended up running about 8 fl oz of engine treatment formula (basically like Seafoam engine treatment formula), into my engine, and then drove it around for about a week. I've since then had a whole lot less blow-by, like barely filling up 1/4 of the catch can per week, that initial week I ran the engine treatment in my oil crankcase.

It's been about 3 weeks now, and the oil in my catch can has basically been non-existent, but still catching some, which is actually totally expected. I've been using tons of AC, idling for long periods, going on long drives... Before this, every 5-7 days would have my oil catch can anywhere from about 1/2 to 3/4 or more full. Now, it barely even catches about an 1/8 of the can that same timeframe.

I was still running that in-line PCV valve that I had rigged up. However, I did take it off today, and will be checking again towards the end of this coming week... I believe the engine treatment formula must've un-stuck my piston rings; which is a surprise, considering I drive the car a bit "spirited", every once in a while. Someone else had also recommended Marvel's Mystery Oil, which I had used in the past year, but to no avail... Maybe this just happened to be the luck I needed..?

[TheBrightSide]

Originally Posted by morepowerjoe

I'm guessing that you've never seen the bottom of your valley cover correct? The reason I know this is because you should have a pcv system under it.
https://www.carparts.com/details/Che...ll%20-%20Parts

https://www.jegs.com/i/Chevrolet-Per...99296/10002/-1

I completely forgot. I was reading about another person's LS3 in this thread: https://www.camaro5.com/forums/showt...=324052&page=7

Looks like the LS3's valley covers do use that internal-styled oil catch can that they designed. Since my blow-by issue didn't change even with adding an in-line PCV valve, but only changed after running an engine treatment formula in the engine itself; I can only assume that the piston rings were stuck.

[TheBrightSide]

I'm about to check my spark plugs and do the compression test soon. Is there a recommendation on whether or not to do a wet or dry compression test on all of the cylinders?

Also, is a leak down test worth doing, to check for issues with valves and such? I've kinda done some slight research, but there's a few varying methods people add to doing leak down tests, like turning the engine and whatnot.

I have not yet replaced anything, and the in-line PCV valve I had added to my "out" routing to the catch can, probably just slowed/reduced the amount of oil blow-by I got. I've since thrown on GM P/N #12594779, which is a rubber PCV breather hose for the LS2 engines. I hate the stupid quick-disconnect crap with the plastic hose that the LS3's came with..

I'll probably double check the intake manifold for oil once I get my car smogged and throw back on my Airaid modular intake tube. I recently snapped off the plastic PCV nipple on the stock LS3 intake manifold, which recirculates from the engine valley cover breather port. To fix this, I stuck a 3/16" plastic hose barb union fitting into the intake manifold PCV nipple port, snugged it, and left a platform for the rest of the snapped portion of the PCV nipple to snag onto. I proceeded to put JB weld around that and the cracked area, which has cured and holds the new breather hose well.

The repaired PCV port is now smaller for the inner diameter (ID), due to the repair obviously, but I doubt that's gonna reduce the amount of oil blow-by by any, if at all... I'll run intake valve cleaner through the intake tube once I finish my smog and re-install my oil catch can...

[larry_g]

Start dry and then add oil if low to see if it's rings or something else. Save the leak down test for any low cylinder to help determine the source of low compression.



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