Catch can installed
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The evidence is deductive reasoning. GM (and every other automaker) has been chasing pcv efficiency since its introduction. Why are they doing this if it does not matter? Why is the ventilation system on c8 almost completely different than c7, which is also very different than c6, if these little bits of oil do not matter?.
It wouldn't surprise me at all if good-ol' JerryU has been tearing his hair out for a couple of days, trying to find even one example of a GM LT engine with anything close to the intake valve buildup of the Audis.
Last edited by Warp Factor; Sep 22, 2020 at 12:18 PM.
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One thing the catch can does is to help prevent large amounts of oil from sloshing into the intake during sustained high G cornering. There are occasions in track where enough oil can slosh into the intake and put the car into limp mode. This can be very dangerous if someone is running nearby an your car suddenly loses power. Catch cans therefore can add some measure of protection against those situations and can have benefit even if you don’t need them for daily driving situations.
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-T
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Aren't all of the Audis (and BMWs, and Subarus) reporting the problem turbo? I wonder if some additional oil is being introduced by the turbo leaking and that is causing the issue. Just thinking out loud here. I know once my son-in-law removed a bunch of emissions things off of his 2016 WRX (including I think part of the PVC system) we instantly noticed blue smoke and even some oil spitting out of the tailpipes. Putting the PVC system back in didn't solve the problem fully, I'm fairly convinced in his case his turbo has a slight leak. Wonder if it could be similar with the Audi/BMWs.
The evidence is deductive reasoning. GM (and every other automaker) has been chasing pcv efficiency since its introduction. Why are they doing this if it does not matter? Why is the ventilation system on c8 almost completely different than c7, which is also very different than c6, if these little bits of oil do not matter?
It matters because valve deposits are real, are accelerated by oil consumption, and further fuel efficiency, oil life, engine life, emissions, and power production are negatively impacted by oil consumption.
Less oil consumption = better across all of these metrics, therefore less oil consumption = better across engines in general (like ours).
If you care about that or not is up to the end user. "Acceptable oil consumption" will always be an opinion, just like embroidered headrests and chrome tail light rings.
It matters because valve deposits are real, are accelerated by oil consumption, and further fuel efficiency, oil life, engine life, emissions, and power production are negatively impacted by oil consumption.
Less oil consumption = better across all of these metrics, therefore less oil consumption = better across engines in general (like ours).
If you care about that or not is up to the end user. "Acceptable oil consumption" will always be an opinion, just like embroidered headrests and chrome tail light rings.
Moreover, I have seen no evidence that catch-cans solve the coking issue in those engines with known problems.
Perhaps there are some good reasons to install them on some engines, for some applications, but insurance against valve coking in gasoline DI engines has not been demonstrated.
Last edited by Foosh; Sep 22, 2020 at 01:01 PM.
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From: Virginia
The evidence is all around if one is willing to look. Gm will say everything is fine until they can get you on the hook for their top end cleaning products / services; Then it is a different story. Again I stress this one thing being focused on here is not the only reason to improve the system. Catch cans are just as popular on port injection.
David, I think your catch cans are really good. Questions remain whether an aftermarket catch can is still needed with the latest developments in OEM oil separation. Evidence that GM LT Direct Injection engines suffer a meaningful buildup on the intake valves is still sorely lacking.
It wouldn't surprise me at all if good-ol' JerryU has been tearing his hair out for a couple of days, trying to find even one example of a GM LT engine with anything close to the intake valve buildup of the Audis.
It wouldn't surprise me at all if good-ol' JerryU has been tearing his hair out for a couple of days, trying to find even one example of a GM LT engine with anything close to the intake valve buildup of the Audis.
Interesting thought, but it wasn't just the turbos. My 2007 RS4, naturally-aspirated, 4.2L V8 with direction injection is the one that required tear-down and walnut shell valve cleaning treatment at about 20K miles.
OK, deductive reasoning is a great way to develop a theory, but that theory must then be subjected to testing and proven (or not) with controlled analyses of data. Deductive reasoning is not evidence. There remains no evidence of a valve coking issue in any of the GM LT engines from the earliest (2013) through present day.
Moreover, I have seen no evidence that catch-cans solve the coking issue in those engines with known problems.
Perhaps there are some good reasons to install them on some engines, for some applications, but insurance against valve coking in gasoline DI engines has not been demonstrated.
OK, deductive reasoning is a great way to develop a theory, but that theory must then be subjected to testing and proven (or not) with controlled analyses of data. Deductive reasoning is not evidence. There remains no evidence of a valve coking issue in any of the GM LT engines from the earliest (2013) through present day.
Moreover, I have seen no evidence that catch-cans solve the coking issue in those engines with known problems.
Perhaps there are some good reasons to install them on some engines, for some applications, but insurance against valve coking in gasoline DI engines has not been demonstrated.
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The evidence is all around if one is willing to look. Gm will say everything is fine until they can get you on the hook for their top end cleaning products / services; Then it is a different story. Again I stress this one thing being focused on here is not the only reason to improve the system. Catch cans are just as popular on port injection.
I have no doubts catch cans are popular in the aftermarket. Some folks do all kinds of unnecessary things to their prized rides because it makes them feel better, and that's just fine. I'm all for folks feeling better. What I don't like is folks being misled into thinking they better add a catch can or else.
Last edited by Foosh; Sep 22, 2020 at 04:59 PM.
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From: Virginia
You said there is no evidence, Well there is plenty, and I found some for you in a moment. Now you change course to needing a 'report'. Come on man.
Who here said they better add a catch can or else? Maybe go haunt threads started by those people instead of this nice person simply sharing his new mod.
Who here said they better add a catch can or else? Maybe go haunt threads started by those people instead of this nice person simply sharing his new mod.
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A word of caution. The forum takes a dim view of ad hominem posts. Be careful when discussing the efficacy of this or that, that the discussion doesn't devolve into ad hominem attacks. People, particularly really good engineers, get passionate about their positions.
Keep it civil.
Keep it civil.
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A word of caution. The forum takes a dim view of ad hominem posts. Be careful when discussing the efficacy of this or that, that the discussion doesn't devolve into ad hominem attacks. People, particularly really good engineers, get passionate about their positions.
Keep it civil.
Keep it civil.
Not knowing much about direct injection engines and oil catch cans, I'm looking for some constructive feedback.
I know some people thought the can wouldn't catch any oil, but clearly it has and I can't imagine that oil would be good for the intake.
Last edited by jjsaustin; Nov 23, 2020 at 09:39 AM.
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I don't think anyone disputes the fact you'll "catch" some oil. The dispute is about whether the tiny amount of oil caught is deleterious to GM LT engines.
There is also no disputing that valve contamination HAS been a problem on some DI engines in the past, just no evidence of a problem on this one. There is also dispute about whether the catch can is a solution to DI valve contamination.
There is also no disputing that valve contamination HAS been a problem on some DI engines in the past, just no evidence of a problem on this one. There is also dispute about whether the catch can is a solution to DI valve contamination.
Last edited by Foosh; Nov 23, 2020 at 10:01 AM.
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From: Virginia
Just saw a vid from Horsepower Obsessed with his oil catch can on his C8 after some 8000 miles and looked to have collected a significant amount of oil.
https://youtu.be/eiui0-Yk-po
Any one thinking of installing one?
https://youtu.be/eiui0-Yk-po
Any one thinking of installing one?
We are pulling just as much oil from the C8 pcv return as previous generations, so if that bothers you then I would say you are in the market!
Mightymouse Solutions catch cans are on both the 1/4 mile worlds fastest C8 and the fastest n/a C8.
https://www.mightymousesolutions.com...t-page/c8-mild
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Following up on this thread: https://www.corvetteforum.com/forums...gine-fire.html
How do I drain the oil in my catch can on the HTC!
Now back to your regularly scheduled catch can debate.
How do I drain the oil in my catch can on the HTC!
Now back to your regularly scheduled catch can debate.
Supporting Vendor
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From: Virginia
Following up on this thread: https://www.corvetteforum.com/forums...gine-fire.html
How do I drain the oil in my catch can on the HTC!
Now back to your regularly scheduled catch can debate.
How do I drain the oil in my catch can on the HTC!
Now back to your regularly scheduled catch can debate.
we have an optional drain extension kit that allows it to be serviced from under the car.
that being said we have not test fit ours on a vert yet. email us! mightymousesolutions@gmail.com
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Wouldn’t this be a much cheaper, less debatable and less risk to the warranty solution?
https://youtu.be/O5N_Z1W6mho
https://youtu.be/O5N_Z1W6mho
From my experience it is still controversial.
I can get on board with periodic treatments like that ahead of build up in addition to stopping everything that I could from happening in the first place.
These are not fool proof products however, still risk, and if GM determined an issue was related to you pouring something / anything in I bet you have a tough case on your hands.
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Install a catch can if it makes you feel better - I have one on my C7 and it does catch some oil in the can. Is it enough to worry about, I can’t say for sure but it Keeps that much oil out of the intake system.
