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Just an interesting observation with my 2.0 for anyone who might care. I installed an oil catch can on my 2019 at approx. 750mi on the odo and I've had to empty it 3 times, each at about 250mi intervals. I was getting very concerned for the amount of oil it was collecting and couldn't get any information online - everyone I asked online had their cans installed well after their engines were broken in. I decided to watch and wait it out over the next few hundred miles, hoping and speculating that the excessive blow by was due to the piston rings. Checking my OCC on my 4th 250mi interval today, at 1,750mi, there was barely a drop of oil in there. First of all, what a freakin relief! I'm not highly literate with engines but from what I've learned through my own research, the connection was the piston rings not being fully sealed yet. I'm open to learning about anything that I may have gotten wrong or misunderstand here, but 1,500 miles seems like a lot for an engine to break in considering all the information floating around about it needing only 750-1,000 miles. My cars been running fine and getting decent mpg since owning it. I hope my next 250mi check returns with similar results!
 

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Interesting theories....

What about weather conditions? Are you now in colder weather?

What about trip lengths? Same driving habits?
 

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First off, the purpose of the catch can is to collect droplets of oil or other products from the crankcase vented by the PCV system. There is always "something" and it has little to do with break-in.

What did the schmoo look like when you did have it? Was it an oily substance, was it red/amber or dark? Was it coffee coloured. Was it the later floating on amber fluid ...

As to break-in it's pretty much done by about 600 miles.

I installed mine when temperatures dropped. Since then all my schmoo has been ... well, here's a photo:

I'm expecting the amount of schmoo to decrease when it gets warmer as well as turn to something more vile looking ...
 

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Interesting theories....

What about weather conditions? Are you now in colder weather?

What about trip lengths? Same driving habits?
Stay and calm suck behind prius traffic driving in warm socal. Trips 60% <20mins/10mi local, 40% 1hr/20mi.

Edit: literally been in the 70's all of Jan

First off, the purpose of the catch can is to collect droplets of oil or other products from the crankcase vented by the PCV system. There is always "something" and it has little to do with break-in.

What did the schmoo look like when you did have it? Was it an oily substance, was it red/amber or dark? Was it coffee coloured. Was it the later floating on amber fluid ...

As to break-in it's pretty much done by about 600 miles.

I installed mine when temperatures dropped. Since then all my schmoo has been ... well, here's a photo:

I'm expecting the amount of schmoo to decrease when it gets warmer as well as turn to something more vile looking ...
Mines clean and pure oil.

Edit: can you not delete a post? How the heck do you do it?
 

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Fine, I'll say it... I'll be crucified by the "catch can brotastic" crowd but I'm gonna say it anyway because it's the stone cold truth...

Catch cans are a waste of time. Save your money for performing maintenance schedule items in a timely fashion and you'll be fine. Trust the Maintenance Minder, it's your friend.

I've seen more than my fair share of engines torn down, with and without catch cans. You can't tell the difference between them. Best case, all the owners were doing was catching cold start condensate that would get burned off anyway as designed - worst case, the warranty was voided (hydrolock due to catch can) and the owner got a brand new engine out of their own pocket for their trouble.

By all means, do what you're gonna do, it's your ride. That said, you'll never convince me that an aftermarket catch can is needed - especially in a modern engine (GDI or otherwise).
 

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OP what did the dipstick tell you?
 

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@johnbell2 As I was at the garage this past week on a separate issue I asked the mechanic about DI residue and he explained their rather expensive procedure for removing said residues from DI cars and that for all that expense one at least gets a very clean set of intake valves, intake manifold and piston tops. He mentioned various models of cars that he's done the procedure on - all European to date. (This is a liquid chemical that's slowly drained into the intake manifold while holding 2000 RPM followed by an oil change (not an option - so I believe it probably cleans the oil ring as well) and a highway speed drive).

Am I a determined catch-canner? Not yet[1]. But it's in the car and I'm removing schmoo. Some of that schmoo would obviously go through (as evaporate or fine mist) and be burned. But some of the schmoo is thicker and would be more likely to stick to the intake valves.

If that bit of avoidance means delaying the above mentioned process to clean the intake valves, etc. by 50,000 km or 100,000 km, then all the better. My sole issue is that, so far, I have to take care to empty the stupid thing every 750 km or so which works out to every other Saturday. We'll see how this goes in the summer and especially on long trips. (By eyeball I could likely go 1000+ km but I'm not risking that). Maybe I'll order a deeper can and/or quick drain.[2]

[1] I've posted links in the past to a catch-can maker's site who decided not to make a catch can for the Honda Civic DI engines. Their analysis is that Honda have designed the function in. It's just not clear to me where the thicker schmoo goes after it's caught.

[2] It would be nice if these things were designed to go to bypass when full. They do have a check valve to prevent reverse flow when the MP is above atmospheric .. even though the article above suggests that's built in to the Honda system (at least on the Civic, but it seems obvious the Accord would have the same scheme).

This was a crucifixion free posting.


OP what did the dipstick tell you?
What have Volvo drivers got to do with this?
 

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I have a catch can (Mishimoto) and empty it regularly (less so in warmer season(s) than colder) and I, as AlantheBeastV2 explains, believe it is better to trap blow by and get rid of it versus recirculate it back through the intake.
Now that the car has 15,000 miles on it I will begin spraying a can of CRC Valve and Turbo cleaner every 5,000 miles. :) And, maybe chrome the catch can, too! All kinds of controversial steps to give occasion to others saying, you're doing it all wrong! :) just kidding
 

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Catch cans do not stop carbon build up on intake valves in GDI engines. Oil film will still make its way past the catch can just like it does the factory air-oil separators that are already in place.

If you have a catch can in the belief you can delay or avoid standard valve maintenance for your K20C4, you're misinformed. It certainly is ineffective under boost when the PCV valve is closed.

It's snake oil. Plain and simple. Save your money to have your engine properly maintained on schedule instead, you'll be better off.
 

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Catch cans do not stop carbon build up on intake valves in GDI engines. Oil film will still make its way past the catch can just like it does the factory air-oil separators that are already in place.

If you have a catch can in the belief you can delay or avoid standard valve maintenance for your K20C4, you're misinformed.
That's your opinion and you're certainly welcome to it. OTOH, whatever I do get out of the catch can has no chance of fouling the intake valves. And yes (as I've stated above) some of the crap I 'catch' will mostly get burned in the chamber. But some of that schmoo is viscous and black and sticky. That's the point.

Fouled intake valves are a well known issue on DI engines. Indeed Toyota and Ford have added port injectors to the DI engines to help mitigate it.

And as I've said before, I'm not convinced of the need for catch cans. But I'll see how that goes over the longer term.

It certainly is ineffective under boost when the PCV valve is closed.
Irrelevant.

When the PCV valve is closed the gases/mist stay in the crankcase "atmosphere". When that valve opens again they can escape to the intake.

I watch my boost via OBD-II: even under some boost when driving at 120 km/hr the manifold pressure is still just below 1 bar (absolute) - so the valve would likely be open. I haven't observed a cruise speed where the boost is above 1 bar (absolute) (yet) because: police.

It's snake oil. Plain and simple. Save your money to have your engine properly maintained on schedule instead, you'll be better off.
Please show me where Honda have a regular maintenance procedure to deal with intake valve fouling?

And, maybe chrome the catch can, too! All kinds of controversial steps to give occasion to others saying, you're doing it all wrong! :) just kidding
If you chrome your catch can the car goes faster but only if you index your spark plugs first.

Edit: clarified boost as being absolute.
 

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Fouled intake valves are a well known issue on DI engines. Indeed Toyota and Ford have added port injectors to the DI engines to help mitigate it.
You have not one, but two engine manufacturers that have gone the hybrid port/direct injection route to address intake valve carbon build up.

If this could be done with a cheaper setup using additional air/oil filtering for open PCV valve operation (e.g. a catch can) they would have done it that way. They didn't... because it doesn't address carbon build up on intake valves in GDI engines.

As I expected, those who went out and purchased a catch can are emotionally invested in it and will defend that purchase to the end. There are no surprises to me in any of the responses I've seen. Anyone who has an engine this new (2018+ 2.0T or 1.5T for that matter) hasn't put enough mileage on it to even begin to determine if a catch can is having the desired effect. Do the tear down after 100k miles with the catch can in place and take pictures of the intake valves and inside of the manifold. Then, compare it side by side with the same engine without a catch can operated under similar mileage / conditions. I can all but guarantee you that there will be little if any difference between the two.

At best, catch cans are a placebo. At worst, they're a warranty denying event waiting to happen. Do what you will, it's your money. To me, it's better spent on following the maintenance schedule / minder for your engine.

And, please stop putting words in my mouth re: the maintenance schedule. I didn't say anything specific about intake fouling. I'm merely stating that budgeting your catch can money to instead follow Honda's maintenance schedule is most likely to yield long engine life.

Btw, when the PCV valve is closed under boost the gasses are pulled from the top of the valve cover. Just fyi. That's why the valve covers are baffled to allow for air/oil separation. Think about that the next time you're perusing your OBDII scanner results.
 

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@johnbell2 sorry you have wadded panty syndrome, I'll try to be sensitive to that. I've said several times that I'm a skeptic on catch cans - but I put one in as a potentially costs savings down the road item.

As to stop putting words into mouths, heal thyself: I never said I wasn't following the Honda maintenance schedule now did I?

As to your last para, that is pretty much bollocks because most of the time boost is not causing the PCV valve to close because most of the time the PCV valve is open. The boost is not high enough often enough to matter in that regard. Funny what you learn observing actual data.
 

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Catch cans do not address carbon build up on intake valves in GDI engines because catch cans have nothing to do with EGR. GDI generates soot. Q.E.D.

Even if catch cans were effective on the PCV side (which they're not, by inspection given manufacturer approaches if nothing else) they would never be able to account for EGR input. This is why many manufacturers are going with the hybrid port/direct injection route. It is the only sure way to keep the backs of the intake valves clean and thus properly address the build up in question. That, or have their customers go through the tear down / clean up of the intake manifold and heads after certain mileage as been reached.

Ultimately, we're back to having to use top tier gas detergents sprayed into the intake ports and the 'tau' fuel build up on the intake runners to keep the intake valves clean. What was old is new again.

I will tell you one thing that catch cans are good at separating... wallets from their money.
 

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catch cans have nothing to do with EGR. GDI generates soot
Was thinking the same thing while reading all this. EGR will gunk up the valves with carbon. Wonder what effect water injection has on GDI valve deposits for turbo engines.
 

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Catch cans do not address carbon build up on intake valves in GDI engines because catch cans have nothing to do with EGR. GDI generates soot. Q.E.D.

Even if catch cans were effective on the PCV side (which they're not, by inspection given manufacturer approaches if nothing else) they would never be able to account for EGR input. This is why many manufacturers are going with the hybrid port/direct injection route. It is the only sure way to keep the backs of the intake valves clean and thus properly address the build up in question. That, or have their customers go through the tear down / clean up of the intake manifold and heads after certain mileage as been reached.

Ultimately, we're back to having to use top tier gas detergents sprayed into the intake ports and the 'tau' fuel build up on the intake runners to keep the intake valves clean. What was old is new again.

I will tell you one thing that catch cans are good at separating... wallets from their money.
I agree that EGR is not addressed (though it can be through similar methods). OTOH, the schmoo I'm catching does have to flow by the valves too. It can't when "caught". Bonus: reduced emissions. (The schmoo goes to Canadian Tire who in turn "recycle" used oil. Environmental credits here not certain).

As to top tier, I use that anyway (Costco, Shell...) - but it has 0 bearing on the intake valves. But it does help keep the fuel system cleaner than not, esp. the DI injectors which are much finer in hole pattern (IIRC).

As to DI cleaning teardown: not needed at all. I described in an earlier post how intake valves are cleaned w/o the necessity ot removing anything. Though it's a couple hours labour + the product. (I didn't ask for the cost of the treatment but I have to go to the garage Tues. morning and I'll try to remember to).
Environmental impact: probably not pretty.

As to the money, it's not much. Not like I'm wasting money on spoilers ...

Wonder what effect water injection has on GDI valve deposits for turbo engines.
What is the injection point?
 

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1. Writing the word "schmoo" should be treated the same as dropping an F-bomb on this page, because it's more annoying.

2. There are a relatively small number of people riding around with catch cans on their cars compared to the MILLIONS of engines that are out there on the road without them. They exist so people can empty them every three weeks and marvel at the fuel mixtures they've collected and now have to dispose of. I bet they are removed once people get sick of dealing with that crap on a regular basis.

3. Comment 2 notwithstanding, people that have purchased these things will swear they're the second coming, because if they don't it would be an admission of wasted time and money. That is to say -- these discussions don't change minds, and only result in more use of the word mentioned in comment 1.
 
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