Oil Catch Can - is it needed?

[Jeepin' John]

Update on my personal experience with the catch cans - i've now removed the second can. First big name brand can had a good amount of blow-by and the can was leaking around the upper-lower can section seal. Second big name brand can was working awesome until it eventually developed the same upper/lower can section seal leak and also busted the line at the swivel joint on the PCV valve end. Oil was leaking out of that swivel joint, dropping down on the exhaust and burning, making a smell.

I'm not sure if anyone else is having any issues or if it's just my engine specifically, but it seems like there is enough resistance on the PCV system to develop pressure causing the can seal leaks and busted swivel fitting / leak.

So for me personally, i'm not going to run a catch can anymore, and already have a few trips on the teraflex CVS line with no problems. Will update if any develop. This line simply adds a "T" that runs to the oil filler neck and prevents oil being pumped into the intake at steep angles. I'm thinking it will reduce some amount of oil in the intake by drawing from a "cleaner" oil filler neck location, but there is going to be oil in the intake.

Just wanted to update if anyone was concerned about some engines having the potential for catch cans to develop pressure and begin to leak oil. Looks like that was the case for mine, given it happened with two different big name cans

Sponsored

 

[just_another_guy]

I appreciate the information and I'm sure others do as well. I've been kicking around the idea of installing a catch can but the issues you described have me thinking twice.

 

[Mac]

I bought this $20 catch can
Ruien Polish Baffled Universal Aluminum Oil Catch Can Reservoir Tank Black https://www.amazon.com/dp/B06XK9PTP7/ref=cm_sw_r_cp_apip_VZmrl2SzXQe6p
Have had it for close to a year and almost 20k miles, no issues and get close to 8 ounces of stuff from it every 5K miles. I installed it by cutting the oem pvc hard line and just clamping some high quality hose over it, no leaks or smell.

 

[TroutFishingInAmerica]

Update on my personal experience with the catch cans - i've now removed the second can. First big name brand can had a good amount of blow-by and the can was leaking around the upper-lower can section seal. Second big name brand can was working awesome until it eventually developed the same upper/lower can section seal leak and also busted the line at the swivel joint on the PCV valve end. Oil was leaking out of that swivel joint, dropping down on the exhaust and burning, making a smell.

I'm not sure if anyone else is having any issues or if it's just my engine specifically, but it seems like there is enough resistance on the PCV system to develop pressure causing the can seal leaks and busted swivel fitting / leak.

So for me personally, i'm not going to run a catch can anymore, and already have a few trips on the teraflex CVS line with no problems. Will update if any develop. This line simply adds a "T" that runs to the oil filler neck and prevents oil being pumped into the intake at steep angles. I'm thinking it will reduce some amount of oil in the intake by drawing from a "cleaner" oil filler neck location, but there is going to be oil in the intake.

Just wanted to update if anyone was concerned about some engines having the potential for catch cans to develop pressure and begin to leak oil. Looks like that was the case for mine, given it happened with two different big name cans

I have given this some thought and I can't figure it out, I just can't understand how this can happen. I do believe it happened, I believe it happened twice like Jeeping John said, but something is wrong somewhere. The catch cans are under a vacuum, not under a positive pressure. If your can seal is bad it should be sucking in air. To bust the line at the swivel joint sounds like positive air pressure, but there should not be any positive air pressure, it should be a vacuum. I imagine my Mishimoto can, under extreme vacuum it might collapse the hoses, oem was a ridged tube. I really don't see how it could achieve that kind of vacuum. Under a positive pressure, which it should not have, I can see it blowing out the can O ring, or blowing out the swivel joint. This is strange, I've never heard of this kind of issue with a catch can. It's a simple vacuum line and you're adding a oil separator in the middle. John, do you have any more details on this? It's weird, I'm curious why this happened.

 

[Jeepin' John]

I have given this some thought and I can't figure it out, I just can't understand how this can happen. I do believe it happened, I believe it happened twice like Jeeping John said, but something is wrong somewhere. The catch cans are under a vacuum, not under a positive pressure. If your can seal is bad it should be sucking in air. To bust the line at the swivel joint sounds like positive air pressure, but there should not be any positive air pressure, it should be a vacuum. I imagine my Mishimoto can, under extreme vacuum it might collapse the hoses, oem was a ridged tube. I really don't see how it could achieve that kind of vacuum. Under a positive pressure, which it should not have, I can see it blowing out the can O ring, or blowing out the swivel joint. This is strange, I've never heard of this kind of issue with a catch can. It's a simple vacuum line and you're adding a oil separator in the middle. John, do you have any more details on this? It's weird, I'm curious why this happened.

It is very odd. I thought the same - everything should be under vacuum and if there is a leak, it will pull air in, not leak oil. But somehow, the system is getting pressurized. Not sure if it's a resistance thing or if it's that i drive like a senior and don't create much intake manifold vacuum, or if contaminants are clogging the cans and building pressure or what. I wasn't having a problem at first - but it developed over time with both cans. Bummer in my oddball case because the "second can" was catching literally everything and working perfectly. Trying to leave names out of my posts because i genuinely think i just have some random problem. I'll see if the teraflex line develops the same problem or not and update you guys. If so, i'll switch back to the oem pcv line and see what happens. In the meantime, i'm all ears. -so far- no leaks with the teraflex line

 

[Jeepin' John]

Just thought of something - i'm going to check the can-to-intake line at some point and make sure it's totally clear

 

[TroutFishingInAmerica]

It is very odd. I thought the same - everything should be under vacuum and if there is a leak, it will pull air in, not leak oil. But somehow, the system is getting pressurized. Not sure if it's a resistance thing or if it's that i drive like a senior and don't create much intake manifold vacuum, or if contaminants are clogging the cans and building pressure or what. I wasn't having a problem at first - but it developed over time with both cans. Bummer in my oddball case because the "second can" was catching literally everything and working perfectly. Trying to leave names out of my posts because i genuinely think i just have some random problem. I'll see if the teraflex line develops the same problem or not and update you guys. If so, i'll switch back to the oem pcv line and see what happens. In the meantime, i'm all ears. -so far- no leaks with the teraflex line

Thanks for the reply, I have (wild ass guess) probably 5k+ on the Mishimoto with no problem, but I'll look at it on a regular schedule now to see if anything starts to develop. Thanks for keeping us posted.

 

[Jeepin' John]

Just checked the second can. It's all free-flowing - can, and both lines

 

[TroutFishingInAmerica]

Just checked the second can. It's all free-flowing - can, and both lines

Thanks John.

 

[just_another_guy]

Installed the UPR catch can & one way valve breather on Friday before putting a couple hundred towing miles on the truck. Not much to say other than that it appears to be working as advertised.

 

[JasonB]

Been running this for about 5 months. I’ve emptied it 3 times and it was full every time. Looks like a chocolate milkshake. Thought they were hype, but sold in how much gunk comes out.

https://www.corsaperformance.com/co...-can-cc0002-jeep-wrangler-jl-jlu-gladiator-jt

 

[ShadowsPapa]

Been running this for about 5 months. I’ve emptied it 3 times and it was full every time. Looks like a chocolate milkshake. Thought they were hype, but sold in how much gunk comes out.

https://www.corsaperformance.com/co...-can-cc0002-jeep-wrangler-jl-jlu-gladiator-jt

If it doesn't look like pure oil then a lot of it was water, condensation.
The prior picture is a perfect example of one doing the job and not filling with what looks like a $5 cup from Starbucks.

 

[Gren71]

im considering the mishimoto can and wanted some thoughts.

2020 sport s with 83,000 miles. I tow pretty often through my 8-9 month camping season and drive 80ish miles for work. %90 highway driving where i always use the cruise control and (believe it or not) do 65mph the whole highway.


I recently did the math and unless I win the lottery this Jt has to last me until it’s around 160,000 miles. I keep regular maintenance intervals and follow the recommended services as they come up by miles.

while swapping out a throttle body spacer I saw the coffee liquid pictured below. Never seen this before in my JT, but to be fair im not in the intake manifold often (really im never in there). Out of curiosity I pulled my wife’s 18’ JLU intake and hers was bone dry (what ever the opposite of gigity is).

so this got me wondering if its worth it to put in a can to pull the excess moisture out of the system before it maybe causes an issue. Or, if nothing else, have a meaningful way to measure and document it for my dealer to possibly address before my 100,000 miles warranty runs out.

i did just have my spark plugs replaced by the dealership as a scheduled maintenance, so perhaps the coffee is s remnant of something to do with that process.

 

[ShadowsPapa]

That looks like water mixed with gas fumes. Condensation.

I checked the oil on mine today - gets oil change tomorrow.
6,000 miles on this oil and it still reads all but full. Can't be pulling in any oil and still reading full.
My 2020 was the same way - read fine between changes.
If it's drawing in oil via the PCV - it would out of necessity have to read lower after thousands of miles.
32 ounces in a quart.
I'm not going to spend money on one. Not when the oil level doesn't drop. If oil leaves the crank case to go anywhere at all, then the level must read lower. Mine doesn't, so it isn't.

 

[AmishMike]

I pull my catch can every couple of thousand miles and it ALWAYS has 3-4 oz in it. Mostly oil and some condensation. Oil level is down proportionately to what I dump out of that can. Put it on at 10k and have 40k on it now.
Other than that, I don’t notice any difference in performance, mpg or anything else.
Throttle body spacer do anything for you?

Sponsored