Oil Catch Can - is it needed?

[ShadowsPapa]

So far, I'm very pleased with it and surprised at how much crap it catches.

It's not supposed to catch crap, it's supposed to catch pure oil that looks exactly like the oil in the pan - not tan.

Keep in mind, if you think it's caught 8 ounces of oil, that means your engine is 1/4 quart low.
If you think it's caught that much every 2 weeks and it adds up to 32 ounces after a while, then your engine has to be at least a full quart low on oil.
Too often people see a "full catcher cup" and it's crap, not oil.
Whatever is in a catch can cup has to equal how low the crankcase is.
I see a lot of "yeah, mine is full every time I check, I catch a lot of oil" but when I ask them if they have to add oil to the engine - no, it's fine. Uh, not possible.
Just making sure people know that the pics on the internet are often not oil so it's not really doing them the good they believe.
Others - I've seen pure oil in some - real bad. (which implies other issues with the engine)

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[mep4wd]

just from research online, my other project cars are all turbo'd so im used to blow by issues. I decided to do some reading up on it for these motors and found some people having some issues. granted most are on the older 3.6 in the jk systems but that's why I was asking if anyone had any issues with these newer designed motors.

I have a 2020 Gladiator Rubicon I have experienced lots of smoke and oil loss when climbing rock shelves. The engine then goes into "limp mode". Recently on Kane creek canyon in Moab while climbing the "hamburger hill" section I not only smoked but lost 2 quarts of oil. Katch can no help. Anybody know a solution to this?

 

[Gren71]

I saw this video today and immediately thought about this thread.

 

[Rdizz]

What do you guys think about this one?

https://www.extremeterrain.com/jlt-jeep-gladiator-v30-black-oil-separator-driver-side-3069d-b.html

I have ran these cans on 2 different 3.5l F150 "ecoboost". I did this because they are turbo. They caught small amounts of pure oil it looked like. In fact i really only had to empty it once a year and the can still wasnt full not even half full tbh. So I was happy with this brand and its function. But I never saw anything Milky at all.

So after reading through this thread this got me thinking is that because this is a quality Can? or is it the difference between the motors? The Fords were direct injection And I think these 3.6L's are port? I really dont want to empty this thing every week.

My Wife also has a 2023 Wrangler with that 2.0 Turbo. I am thinking for that motor it is a must have?

 

[ShadowsPapa]

What do you guys think about this one?

https://www.extremeterrain.com/jlt-jeep-gladiator-v30-black-oil-separator-driver-side-3069d-b.html

I have ran these cans on 2 different 3.5l F150 "ecoboost". I did this because they are turbo. They caught small amounts of pure oil it looked like. In fact i really only had to empty it once a year and the can still wasnt full not even half full tbh. So I was happy with this brand and its function. But I never saw anything Milky at all.

So after reading through this thread this got me thinking is that because this is a quality Can? or is it the difference between the motors? The Fords were direct injection And I think these 3.6L's are port? I really dont want to empty this thing every week.

My Wife also has a 2023 Wrangler with that 2.0 Turbo. I am thinking for that motor it is a must have?

A good can will be less prone to collecting condensation because of heavier build, not fast extreme temperature changes.
But the reason you saw so little oil was because there was so little to catch.
Most engines with properly operating PCV systems, and that are in good physical condition will little blow-by won't "need" one.
Here's how I figure I don't need one - I don't need to add oil between changes. That means it's not being pulled through a defective PCV and I don't have excessive blow-by.
If I had to add oil, and there were NO leaks, then you safely assume it's going somewhere - and a catch can can catch if before it gets ingested and burned - if it's due to a PCV system problem.

Seems no one really posts their photos showing exactly what they are catching, nor do they log and report how many miles it is, and so on. All you get is "mine catches a lot" but no pictures, and how much is a lot, and over how many miles? Maybe some are afraid to give photos and details because it may show they are collecting condensation and only a tiny bit of oil.

Why would a catch can be a must have on the 2.0 turbo? Do you have to add oil to it between changes?

In order for a catch can to collect oil, it's got to come from the crankcase - so if it's never low, then it's not being pulled out of the crankcase.

 

[Rdizz]

A good can will be less prone to collecting condensation because of heavier build, not fast extreme temperature changes.
But the reason you saw so little oil was because there was so little to catch.
Most engines with properly operating PCV systems, and that are in good physical condition will little blow-by won't "need" one.
Here's how I figure I don't need one - I don't need to add oil between changes. That means it's not being pulled through a defective PCV and I don't have excessive blow-by.
If I had to add oil, and there were NO leaks, then you safely assume it's going somewhere - and a catch can can catch if before it gets ingested and burned - if it's due to a PCV system problem.

Seems no one really posts their photos showing exactly what they are catching, nor do they log and report how many miles it is, and so on. All you get is "mine catches a lot" but no pictures, and how much is a lot, and over how many miles? Maybe some are afraid to give photos and details because it may show they are collecting condensation and only a tiny bit of oil.

Why would a catch can be a must have on the 2.0 turbo? Do you have to add oil to it between changes?

In order for a catch can to collect oil, it's got to come from the crankcase - so if it's never low, then it's not being pulled out of the crankcase.

To answer your last question, Only because from what I know about the 2.0L turbos is they are direct injection. She hasn't come up to her first oil change yet, only around 2500 miles. But the main question is not really a matter of a "must have" as I put it but a matter of preventative maintenance. But from what I read turbo engines with direct injection greatly benefit from having one.

And as far as the naturally aspirated 3.6 with Port injection maybe not so much. But some of these pictures I see on here and online are so extreme compared to what I saw on my F150 really starts to make me wonder if this is something I should Do on the 3.6. On mine I have about 15k miles.

And all of this is just preventative measures, just thinking less crap that goes back in could only help, right? I think back in the day this stuff used to just vent to atmosphere and it was rerouted to be more environment friendly. So this mess really was never meant to go back into the engine to begin with.

am I making sense, Hard to do this from my phone.

 

[kentompkins]

Warning to the masses. I had cans on my Tahoe and Suburban. Worked great. No regrets. Just hit 10,000 miles on my JT with a kit from UPR (pretty good reputation and quality product). Just got O2 sensor code. Shop (and I) confirmed that the braided cost connecting this can to the PCV valve leaked after about 8,000 miles. Fouled the sensor. Out at least $100 and time. Will not put can back on. It caught a LOT of oil so I wish this had worked.

 

[wuykats]

Man, this is a looonnngg thread. Very interesting, just wondering if it might be better to install a new PCV valve on a regular basis. The Mopar part is available on Rock Auto for 25 bucks or so, seems we need to really be sure we have a properly functioning valve to maintain that vacuum in the system.

 

[Maximus Gladius]

Man, this is a looonnngg thread. Very interesting, just wondering if it might be better to install a new PCV valve on a regular basis. The Mopar part is available on Rock Auto for 25 bucks or so, seems we need to really be sure we have a properly functioning valve to maintain that vacuum in the system.

My experience with Rock Auto is to send parts back for not working and then have to just pay full price and get the OE one. What do you mean by changing on a regular basis? You’d have to know somehow it’s failing and changing my PCV for a new one didn’t make a lic of difference in the oil my catch can caught.

The only difference in the amount I caught was to change from 0/20 to 5/30. I was catching 250ml in 5000 klm (3000 miles), then after switching to 5/30, it caught 150ml in the same milage.

 

[Maximus Gladius]

I used to think I didn’t need a catch can but out of boredom and needing to tinker on the truck, I put one in and saw the oil. There’s no talking yourself out of it once you see it and then there’s all the warm and fuzzy feelings I got knowing I wasn’t burning this oil and contributing to global warming like my leaf blowing neighbour every time he fires that thing up.

The good thing about a catch can is that it’s super easy to put on and the same easy to pull it off if you don’t like it.

 

[ShadowsPapa]

Man, this is a looonnngg thread. Very interesting, just wondering if it might be better to install a new PCV valve on a regular basis. The Mopar part is available on Rock Auto for 25 bucks or so, seems we need to really be sure we have a properly functioning valve to maintain that vacuum in the system.

Get a QUALITY PCV - not an el-cheapo.
These are engineered for a specific amount of flow at various inches of Hg (vacuum)
There used to be published specs for a lot of engine PCV valves.
They should not be treated as a life-time part of the engine expecting 100,000 miles out of them.
They can get dirty, gummy, they can wear, the springs become weak and so on.
And, sometimes the specs change over the years as more "real use" info becomes available.. More than one company has changed the PCV specs after a few years of an engine being out there as they learn more and gather more data.
I think people have become accustomed to forgetting about them - go back 35 years and you would see cabinet of various part numbers of PCV valves. I have such a cabinet in my shop. It used to hold dozens of different numbers of PCV valves. But some engines, such as the 4.0, actually used a set size orifice instead of a valve, and the PCV became less common.
That doesn't mean it should not be paid attention to.

To answer the topic or subject question? No, for the vast majority, a proper, well-maintained, working PCV is plenty. Think of the MILLIONS - literally millions - of these engines out there, no issues, no catch can. And like each of those I've owned over the years - the oil level doesn't drop between changes.
If these were DI, it might be a different story, but maybe not..
I also believe a lot of what goes on depends on the DRIVER, how the engine is used, the vacuum levels, loads, RPM and other factors. You may use a Jeep in a way that's outside of the norm - and then a stock PCV may not function real well.
No one can say "it's needed", and no one can say "it never helps", either.

 

[RacerAV]

Get a QUALITY PCV - not an el-cheapo.
These are engineered for a specific amount of flow at various inches of Hg (vacuum)
There used to be published specs for a lot of engine PCV valves.
They should not be treated as a life-time part of the engine expecting 100,000 miles out of them.
They can get dirty, gummy, they can wear, the springs become weak and so on.
And, sometimes the specs change over the years as more "real use" info becomes available.. More than one company has changed the PCV specs after a few years of an engine being out there as they learn more and gather more data.
I think people have become accustomed to forgetting about them - go back 35 years and you would see cabinet of various part numbers of PCV valves. I have such a cabinet in my shop. It used to hold dozens of different numbers of PCV valves. But some engines, such as the 4.0, actually used a set size orifice instead of a valve, and the PCV became less common.
That doesn't mean it should not be paid attention to.

To answer the topic or subject question? No, for the vast majority, a proper, well-maintained, working PCV is plenty. Think of the MILLIONS - literally millions - of these engines out there, no issues, no catch can. And like each of those I've owned over the years - the oil level doesn't drop between changes.
If these were DI, it might be a different story, but maybe not..
I also believe a lot of what goes on depends on the DRIVER, how the engine is used, the vacuum levels, loads, RPM and other factors. You may use a Jeep in a way that's outside of the norm - and then a stock PCV may not function real well.
No one can say "it's needed", and no one can say "it never helps", either.

Sir...
1. Miss reading your comments.
2. I rushed to this thread tonight because I randomly decided to check my Ripp catch can, and holy crap it's FULL. I've got maybe a few thousand miles on the set up, no way it should be that full right?
3. Do I need the can AND the Teraflex additional PCV set up?

... frustrated...

 

[ShadowsPapa]

Sir...
1. Miss reading your comments.
2. I rushed to this thread tonight because I randomly decided to check my Ripp catch can, and holy crap it's FULL. I've got maybe a few thousand miles on the set up, no way it should be that full right?
3. Do I need the can AND the Teraflex additional PCV set up?

... frustrated...

I'm not sure what the capacity of their unit is - but if by a few you mean 5,000 or less miles, it sounds like a lot - if -
It is all truly oil. If it looks just like what would be on the dipstick or what would come out if you pulled the drain plug and wasn't a tan or brown look.
So many end up catching a lot of condensation, it ends up being mostly water in an emulsion.

Not sure what year JT you have, but make sure it's running the latest PCV valve first.
Go from there.

 

[RacerAV]

I'm not sure what the capacity of their unit is - but if by a few you mean 5,000 or less miles, it sounds like a lot - if -
It is all truly oil. If it looks just like what would be on the dipstick or what would come out if you pulled the drain plug and wasn't a tan or brown look.
So many end up catching a lot of condensation, it ends up being mostly water in an emulsion.

Not sure what year JT you have, but make sure it's running the latest PCV valve first.
Go from there.

It's a small can, maybe 8-10 oz or so? Yeah I've got maybe 3500 miles on this set up. I'll have better data soon, changing oil in a week or two. It was definitely oil, dark, black, nothing else, mostly. The VERY bottom had a small bit of tan sludge, very little though. Probably the air and water frothy mix...

I've got a 2023 Mojave. Never changed the PCV.

 

[AmishMike]

Racer, do you drive gently?
I drive my 2020 Rubicon like an old lady which creates a lot of vacuum and my catch can (3 oz? Mishimoto) fills in a few thousand miles. Has since 15k, has 95k on it now.

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