Catch Can Skeptic

[Silverado-Hareek]

I hat to add fuel to a catch can debate.  I can say that the first time I ever emptied mine, it was in December and I drained 6 oz of fluid that had the very milky coffee look. Meaning it was mostly water and the typical 1-2 oz of oil.  I drained it into one of those oil drain pans and left it outside overnight.  The next morning the mixture was frozen solid.  So i'd argue yes it can freeze in your catch can given the right moisture content.  However, at least with an RX can, the inlet port is at the top and the outlet port is at the top so unless the can is 100% full of liquid, even if the liquid freezes you shouldn't block the air flow through the can, you would only have diminished oil catching capabilities because not as much would pass through the filter media.  So over pressurization of the crankcase shouldn't be a problem.  With that being said, I still recommend knowing your can's limits and understanding how long you can go in certain temperatures before emptying it and make sure it doesn't get overfilled.  Generally, I go about 3,000 miles in mid July before emptying it and about 500 miles in the dead cold of winter before emptying it.  And I scale inbetween that range depending on temperatures.

 

I don't know of any studies that prove engines with catch cans are better off than engines without them.  I've read enough to fall into the camp that thinks if it's catching oil, then that oil isn't getting baked onto your valves and that's a good thing.  Whether it matters in the long run or not, I'm not sure we can really say one way or the other because no one has done a true scientific experiment to prove it.  But, companies like Toyota are designing solutions to clean the valves on DI engines so the industry recognizes that DI has an inherent design flaw with valve buildup that needs to be addressed.  The toyota solution is to use a combination port injection/direct injection setup where at certain intervals, the engine sprays fuel on the valves to clean them, then changes back over to direct injection.  I'm finding it increasingly difficult not to become a Toyota owner haha

[SS502]

1 hour ago, JimCost2014 said:

 Question has nothing to do with consumption. Question was asking how much oil do you add, meaning how much oil is accumulating in the can? "Common Sense" would be if it is catching a substantial amount (say a quart or more, remember, the majority of us without them are idiots) it would be a good investment, 1/4 of a quart, don't see the point.

 

1 hour ago, JimCost2014 said:

Sorry, was not clear with my question, how much total oil in the catch can between oil changes, oil that does not filter back into the engine and needs to be replaced to bring the level to full?

Jim, I do not add anything. Idiots was your words not mine. No that oil does not get filtered back into the engine crank case (although GM has a new system that does) It gets sucked into your intake, through your intake valves and into your cylinder and then burned up and expelled through the exhaust. Thus it doesn’t matter how much is in your can, it would be the same amount that gets “used” anyway. That’s why I mentioned consumption. With or without a can you’re using the same amount of oil. Hope this helps.

Edited March 29, 2019 by SS502
Typo

[Silverado-Hareek]

I will add that if you're looking for a manufacturer like GM to study catch cans, you're barking up the wrong tree.  Most engines go well past the warranty period without valve building up being a problem.  No way GM or anyone is going to spend $50 per vehicle to install a part that adds maintenance effort for the customer and has no impact on the performance of the vehicle while under warranty.  Something like a catch can is left to the aftermarket to study and decide if it's a worthwhile upgrade or not.

Edited March 29, 2019 by Silverado-Hareek

[TXGREEK]

Better explained

https://www.enginebuildermag.com/2017/10/solving-gasoline-direct-injection-issues-facts-fictions-gdi/


Sent from above

[CSI-WALLEYE]

9 minutes ago, Silverado-Hareek said:

I will add that if you're looking for a manufacturer like GM to study catch cans, you're barking up the wrong tree.  Most engines go well past the warranty period without valve building up being a problem.  No way GM or anyone is going to spend $50 per vehicle to install a part that adds maintenance effort for the customer and has no impact on the performance of the vehicle while under warranty.  Something like a catch can is left to the aftermarket to study and decide if it's a worthwhile upgrade or not.

Don't you think that GM would care if their vehicles failed right after warranty?  It would not do much for sales.

[SS502]

3 minutes ago, CSI-WALLEYE said:

Don't you think that GM would care if their vehicles failed right after warranty?  It would not do much for sales.

No I do not.

[SS502]

24 minutes ago, mookdoc6 said:

90% of what is in the catch can is not oil.......

Go back a few posts and see my results....that’s not 90% of other stuff. If anything I’d say 80% oil, 15% fuel and 5 % water. I don’t live in a cold environment so I don’t get much water.

[NCPGMC]

 

 

 

[SS502]

6 minutes ago, NCPGMC said:

 

 

 

Nasty...can’t stand someone chewing with their mouth open 

[BigBlueLB756]

It's Friday.

Forgive me, father, for I have modded.

Edited March 29, 2019 by BigBlueLB756

[JimCost2014]

Just to be clear, at 10,000 miles my engine is not using/losing any oil between changes.

 

Now everyone back to puffing up their chests and preaching their ideas are the best ever heard.....

[JimCost2014]

1 hour ago, SS502 said:

 

Jim, I do not add anything. Idiots was your words not mine. No that oil does not get filtered back into the engine crank case (although GM has a new system that does) It gets sucked into your intake, through your intake valves and into your cylinder and then burned up and expelled through the exhaust. Thus it doesn’t matter how much is in your can, it would be the same amount that gets “used” anyway. That’s why I mentioned consumption. With or without a can you’re using the same amount of oil. Hope this helps.

Unfortunately it does not help, because it does not answer my question. 6 ounces of contaminated fluid will ruin an engine, even though you still have 250 ounces of good oil circulating through the engine?. 

[SS502]

4 minutes ago, JimCost2014 said:

Unfortunately it does not help, because it does not answer my question. 6 ounces of contaminated fluid will ruin an engine, even though you still have 250 ounces of good oil circulating through the engine?. 

How is that 6 ounces getting back to your crank case to contaminate the other 250?

[JimCost2014]

1 minute ago, SS502 said:

How is that 6 ounces getting back to your crank case to contaminate the other 250?

Yes sir, you win, I am not even sure how to post a question anyone can understand. Enjoy your 10000000000000 miles trouble free driving because an after market company sold you a product that they can not afford to even do tests on. 

[L86 All Terrain]

1 hour ago, Silverado-Hareek said:

I will add that if you're looking for a manufacturer like GM to study catch cans, you're barking up the wrong tree.

GM installs catch cans on all boosted V8's, and perhaps even the LT1 cars if I am not mistaken. All LT4/5 cars are equipped with catch cans from what I have been told. So they have done the research, they know it works. But they also know your 6.2L Silverado is not going to hit the road course once a month and spend a few hours above 4,000rpm like a Z06 or 1LE owner does. If they can put out a product cheaper, they will. That includes holding back goodies that may make your vehicle last longer. The quicker we destroy them, the sooner we are back at the dealer buying another one, the automakers know that as much as we do.