Catch Can Skeptic

CSI-WALLEYE · March 28, 2019

I am new to the Forum and have a 2017 Sierra with 12K on it. I understand the principle behind the catch can and it makes sense. The problem I have is that there is a lack of evidence that it actually does what it says it will do. I have no doubt it removes water and oil but does it actually reduce the carbon build up on your valves? With the amount of money involved in selling an promoting these things I can believe that someone has not performed any type of controlled scientific study. It would be simple for a company with a fleet of vehicles to take a group on new trucks and have some with and without catch cans. After a certain amount of time or mileage you look at the valves and scientifically measure the amount of carbon on the valves. I have not been able to find such a study. does anyone know of the existence of one?

Alternatively, does anyone on the forum have a GDI truck with high mileage that does not have any carbon fouling problems? How are you managing you maintenance?

I have no problems installing a catch can but I would like some actual proof that it does what it says it does.

SS502 · March 28, 2019

On ‎3‎/‎22‎/‎2019 at 5:08 PM, SS502 said:

Emptied my RXP dual catch can...this is at 650 miles. I’ve posted the 100, 400 and now 650 miles. This is a total, I have been keeping a running total.

10 minutes ago, CSI-WALLEYE said:

I am new to the Forum and have a 2017 Sierra with 12K on it. I understand the principle behind the catch can and it makes sense. The problem I have is that there is a lack of evidence that it actually does what it says it will do. I have no doubt it removes water and oil but does it actually reduce the carbon build up on your valves? With the amount of money involved in selling an promoting these things I can believe that someone has not performed any type of controlled scientific study. It would be simple for a company with a fleet of vehicles to take a group on new trucks and have some with and without catch cans. After a certain amount of time or mileage you look at the valves and scientifically measure the amount of carbon on the valves. I have not been able to find such a study. does anyone know of the existence of one?

Alternatively, does anyone on the forum have a GDI truck with high mileage that does not have any carbon fouling problems? How are you managing you maintenance?

I have no problems installing a catch can but I would like some actual proof that it does what it says it does.

A simple Google search can show you all sorts of DI intake valves with build-up. Not going to try to persuade you either way but the fact that other manufactures have gone to DI along with the older PI (it's a dual system) and GM designing an internal system should tell you plenty. I doubt you will find a specific controlled scientific study on the K2 trucks but (not trying to be a smart@ss) I don't need to rub poison oak all over my face to know I'm gonna have some itching really soon. The above picture is from only 650 miles on my personal truck. Even if it somehow didn't get baked onto the valves, I don't want it being sucked down my intake and into the combustion chamber. It's a personal choice obviously and one that I made for me. I believe that @Snowcamo is going to be tearing down his intake (if not already) and I asked him to take pictures, he is at about 100K but I am not sure if he runs a can or not. I plan on bore scoping my intake at 20K just to see how well OR bad my catch can is or isn't working. I didn't provide you with a study you seek but I did give you a nice long answer to help pass the time LOL

Nitrousbird · March 28, 2019

Or use simple logic. If oil isn't hitting the valves, what would be building up on them? Exactly.

If you reduce the amount of oil hitting the valves, common sense would tell you that your reduced the build up on the valves.

You have seen the proof of catch cans catching oil. That is oil heading towards your intake. That should be enough reason to know this should be used.

GM even puts a catch can (be it an unfortunate design that dumps into the sump) on some of its DI motors. So GM thinks they are worthwhile as well.

Jacoby · March 28, 2019

See picture above from SS502 and the "simple" logic Nitrousbird pointed out. That should be all the evidence you need.

imiller1974 · March 28, 2019

I've been running a catch can on my truck since day 1. Empty it out once a week. I still had a puddle of oil in the bottom of my intake manifold when I pulled it off to bolt on the supercharger. There was still carbon build up on the back of the intake valves, not much, but some... Less than a 1/32" on some spots on the valve at most...

SS502 · March 28, 2019

2 minutes ago, imiller1974 said:

I've been running a catch can on my truck since day 1. Empty it out once a week. I still had a puddle of oil in the bottom of my intake manifold when I pulled it off to bolt on the supercharger. There was still carbon build up on the back of the intake valves, not much, but some... Less than a 1/32" on some spots on the valve at most...

None of them are 100% not sure what brand you had but imagine (if you emptied weekly) what they would have looked like without it??

Snowcamo · March 28, 2019

8 minutes ago, SS502 said:

A simple Google search can show you all sorts of DI intake valves with build-up. Not going to try to persuade you either way but the fact that other manufactures have gone to DI along with the older PI (it's a dual system) and GM designing an internal system should tell you plenty. I doubt you will find a specific controlled scientific study on the K2 trucks but (not trying to be a smart@ss) I don't need to rub poison oak all over my face to know I'm gonna have some itching really soon. The above picture is from only 650 miles on my personal truck. Even if it somehow didn't get baked onto the valves, I don't want it being sucked down my intake and into the combustion chamber. It's a personal choice obviously and one that I made for me. I believe that @Snowcamo is going to be tearing down his intake (if not already) and I asked him to take pictures, he is at about 100K but I am not sure if he runs a can or not. I plan on bore scoping my intake at 20K just to see how well OR bad my catch can is or isn't working. I didn't provide you with a study you seek but I did give you a nice long answer to help pass the time LOL

Yep im gonna pull mine. Ordering the intake gaskets friday. No catch can here, but if my intake valves are dirty ill put one in.

CSI-WALLEYE · March 28, 2019

Hey Guys,

I appreciate the responses. I am actually leaning toward buying an E2. However this is just as a safety measure because I have not seen evidence that cans cause any harm. However, correlation does not prove causation. I remain skeptical because there is no data to show reduction in deposits. Don't you think it is curious that there is an entire industry built on this piece of equipment with not actual study to show it actually works? Sure the oil in the can is a good indicator, but it shows that it catches oil and not that it prevents deposits. It could be that the oil is burned in the normal operation of the engine and that there is no difference between using a can or not. You really can't know the outcome until you perform a study designed to answer the question. By the way, I would not be surprised if they actually do work. I just remain skeptical until I see proof. Does that not make sense?

I was hoping that there was a study out there that I had missed.

SS502 · March 28, 2019

3 minutes ago, CSI-WALLEYE said:

Hey Guys,

I appreciate the responses. I am actually leaning toward buying an E2. However this is just as a safety measure because I have not seen evidence that cans cause any harm. However, correlation does not prove causation. I remain skeptical because there is no data to show reduction in deposits. Don't you think it is curious that there is an entire industry built on this piece of equipment with not actual study to show it actually works? Sure the oil in the can is a good indicator, but it shows that it catches oil and not that it prevents deposits. It could be that the oil is burned in the normal operation of the engine and that there is no difference between using a can or not. You really can't know the outcome until you perform a study designed to answer the question. By the way, I would not be surprised if they actually do work. I just remain skeptical until I see proof. Does that not make sense?

I was hoping that there was a study out there that I had missed.

Last post, I promise but just how is it going to get burned if it doesn't get introduced into the combustion chamber via your intake valves? The old Port Injection used to wash the valves off DI does not.

Edited March 28, 2019 by SS502

1SLOW1500 · March 28, 2019

I've been running a catch can on my truck since day 1. Empty it out once a week. I still had a puddle of oil in the bottom of my intake manifold when I pulled it off to bolt on the supercharger. There was still carbon build up on the back of the intake valves, not much, but some... Less than a 1/32" on some spots on the valve at most...

Something isn't right with this.
I am pro catch can. There is no question at all it helps. My friends and family in auto industry agree as donevery performance shop ever.
That said install I find a issue. Also in my option the css is mandatory. Then the issue is what is the vacuum source? I have one line with a check valve and believe me it can suck the paint off. But if that source is intake then whatever that percent is it goes back into intake.
I should take a video. I drain mine and it is a cup of water mixed with oil and depending on temp I can do that every day.

Sent from my SM-N960U using Tapatalk

SS502 · March 28, 2019

10 minutes ago, 1SLOW1500 said:

Something isn't right with this.
I am pro catch can. There is no question at all it helps. My friends and family in auto industry agree as donevery performance shop ever.
That said install I find a issue. Also in my option the css is mandatory. Then the issue is what is the vacuum source? I have one line with a check valve and believe me it can suck the paint off. But if that source is intake then whatever that percent is it goes back into intake.
I should take a video. I drain mine and it is a cup of water mixed with oil and depending on temp I can do that every day.

Sent from my SM-N960U using Tapatalk

Man, I gotta break a promise...wasn't gonna post anymore in this thread BUT...I too am a CSS believer although my CSS is it's own second can but functions the same with the tiny additional catch, doesn't catch a lot but it's not really used as much. I saw yours, you have the valve covers bridged as do I. They both work great IMHO.

1SLOW1500 · March 28, 2019

Man, I gotta break a promise...wasn't gonna post anymore in this thread BUT...I too am a CSS believer although my CSS is it's own second can but functions the same with the tiny additional catch, doesn't catch a lot but it's not really used as much. I saw yours, you have the valve covers bridged as do I. They both work great IMHO.

Like a breather? I now have both valve cover ports and the css going to a breather tank.

Sent from my SM-N960U using Tapatalk

SS502 · March 28, 2019

6 minutes ago, 1SLOW1500 said:

Like a breather? I now have both valve cover ports and the css going to a breather tank.

Sent from my SM-N960U using Tapatalk

No, I bridged the valve covers, T fitting off that to the small can then to the intake air box with a check valve. Most CSS go from the oil fill cap valve cover to the air box. I assume your breather tank eventually gets some in it?

1SLOW1500 · March 28, 2019

No, I bridged the valve covers, T fitting off that to the small can then to the intake air box with a check valve. Most CSS go from the oil fill cap valve cover to the air box. I assume your breather tank eventually gets some in it?

See that is that one line back to intake issue. But so far it says clean. But its many feet of 5/8" line no t and a large breather tank. So it takes a lot for oil to make it there.
All my valve cover ports including the css go to breather. Only the valley port goes to can. And to the intake manifold.

Sent from my SM-N960U using Tapatalk

Jacoby · March 28, 2019

1 hour ago, CSI-WALLEYE said:

Hey Guys,

I appreciate the responses. I am actually leaning toward buying an E2. However this is just as a safety measure because I have not seen evidence that cans cause any harm. However, correlation does not prove causation. I remain skeptical because there is no data to show reduction in deposits. Don't you think it is curious that there is an entire industry built on this piece of equipment with not actual study to show it actually works? Sure the oil in the can is a good indicator, but it shows that it catches oil and not that it prevents deposits. It could be that the oil is burned in the normal operation of the engine and that there is no difference between using a can or not. You really can't know the outcome until you perform a study designed to answer the question. By the way, I would not be surprised if they actually do work. I just remain skeptical until I see proof. Does that not make sense?

I was hoping that there was a study out there that I had missed.