Catch Can Question

[tomm.brz]

catch cans arent there to actually save an engine, some oil mixed with the fuel won't cause disruptive detonations out of nowhere

if you have real knock problems, you need failsafes and/or tune revisions to fix that, or better fuel etc.. A good tune will correct eventual knocks caused by those vapours

It 's just that we know crank vapours re-entering the combustion chambers can make the fuel quality worse specially when you drive hard for long so they just aid in keeping the "charge" as clean as possible

[x808drifter]

The real reason most cars don't have one is because
A: It does very little in the long run on a daily car.

B: It's just another thing to go wrong when the typical owner doesn't drain it.

If you have oil in the intake get one. Then find out WHY you have blow by.

IMO a catch can is for monitoring engine health.
Little to no blow-by. Healthy engine.
Lots of blow-by? Something is wrong.

Wiseco has a good article on blow-by and it's causes.
http://blog.wiseco.com/common-causes...il-consumption

TLDR;

Despite many of these gadgets that are often can be as much prestige bling items as functional, the best way to control crankcase pressure and vapors is to minimize the leakage past the rings. That will do more to improve performance and operate with a cleaner engine than anything else you can do.

[scion fr-s]

Generally, blow-by occurs when oil passes through the piston ring seal. I am sure there are more reasons as to why blow-by can occur. I use catch cans as a way to monitor the health of my engine.

[MotoX16]

Originally Posted by DarkPira7e

I ran one on my NA car. Didn't catch anything unless I was hammering it hard; still didn't accumulate much, but I'd rather keep anything I can catch out of my intake.
I used the Radium PCV side can. I vent the crankcase side to atmosphere and have never had anything show up in that line, NA or turbo. I think each car will have its own propensity for blow-by; I know that mine does so it helped me.

The idea is that oil vapor gets forced into the intake. Our systems recycle this, and oil lowers octane rating- eventually possibly leading to an issue.
If you plan on beating the car, it's worth the small investment to have one on the PCV side at least, in my opinion.

Does your catch can throw a cel? I just took the turbo kit off my car but left the catch can (fbm) because I didnt have the parts to return that to stock, and I'm getting a P0452 (evap) code. Not sure if its something to do with the catch can using the pcv system or not

[DarkPira7e]

Originally Posted by MotoX16

Does your catch can throw a cel? I just took the turbo kit off my car but left the catch can (fbm) because I didnt have the parts to return that to stock, and I'm getting a P0452 (evap) code. Not sure if its something to do with the catch can using the pcv system or not

No, the catch can shouldn't cause anything like that. Make sure you reconnect the solenoid that was probably connected to your boost control solenoid back to the original CPC under the intake manifold

[MotoX16]

Originally Posted by DarkPira7e

No, the catch can shouldn't cause anything like that. Make sure you reconnect the solenoid that was probably connected to your boost control solenoid back to the original CPC under the intake manifold

huh...I did that. I still have a flexfuel kit hooked up too could that have something to do with it? Otherwise I'll start checking for vacuum leaks but I'm pretty sure I got everything hooked back up

[DarkPira7e]

Originally Posted by MotoX16

huh...I did that. I still have a flexfuel kit hooked up too could that have something to do with it? Otherwise I'll start checking for vacuum leaks but I'm pretty sure I got everything hooked back up

Flex fuel very well could be why, most people just disable the code with tuning software.

[NoHaveMSG]

Originally Posted by MotoX16

huh...I did that. I still have a flexfuel kit hooked up too could that have something to do with it? Otherwise I'll start checking for vacuum leaks but I'm pretty sure I got everything hooked back up

If your flex fuel is evap reference, then yes, this is what is causing the code.

[MotoX16]

Originally Posted by NoHaveMSG

If your flex fuel is evap reference, then yes, this is what is causing the code.

It is, thanks. Was able to find the install document laying that out. Appreciate the help!

[Overdrive]

My car is NA, and for me the can is a good way for me to pay attention to how the engine is doing in between oil changes. It spends most of its life daily driving, typical city and highway mix, and maybe a few autocrosses a year. Seeing how much water, fuel and oil accumulates in the can (especially during the winter) I don't feel it's a waste. Absolutely necessary? No, but not gonna knock anyone for installing one and putting it to good use.

During the winter it seems I get a lot more moisture going through the intake and getting trapped in the can, so I usually end up emptying the can at least once before my oil change, and it looks like someone poured way too much milk in their coffee, with some sketchy looking solid looking chunks of white goop in the bottom. During the warmer seasons I'll usually only have to empty it out once, typically when it's time to change the oil, the color is much darker, and haven't had it get close to being full yet.

Is it going to make an epic, world-changing difference in the long run? Probably not, but I'm not upset about the little bit / lot a bit that it does capture and keep out of the engine.