Thrash

I ordered the "see-through" catch-can and installed it 3 days ago. After about 125 miles of driving (some 20 miles being spirited) the cup is already about 1/3 full? I checked it this morning and took the photo.

Seems to be a lot, what do you think? Does this seem normal? Maybe I need a bigger can, as the jar is only 2.5" tall?

Lastly I'm supposed to pour the oil back into the crankcase, right?

Thanks O' Great Forum ...

Thrash

FloydSummerOf68

I'd say it was a needed purchase

taken19

My see through was about half full in about 100 miles of spirited driving. I thought that was a bit much, but it looks like you are I the same boat as me. When I pulled my heads for a H/C swap, I couldn't believe the amount of carbon buildup on the pistons, most likely attributed to the oil.

I would not pour the oil back in. There is a possibility that it could have contaminants in it and I wouldn't take the risk.

Boomer111

That just nuts!

Catch cans are not CARB approved in California.

Thrash

Thanks much, really love the forum ...

taken19

This was after about 100 miles of driving. Notice the specs of dust/dirt mixed in - that's why I wouldn't re-use. Just chalk it up to "used" oil...





Pics when I first popped the stock heads off at 38k miles. The catch can was only installed about 1000 miles at this point. There were places where the carbon buildup was 1/16" thick! I couldn't believe it for such low mileage.

Remember that these carbon deposits can cause hot spots and create detonation and reduced engine performance. I have recently switched to an Elite Engineering catch can, a much better design and much larger catch reservoir. This means less frequent dumps. I couldn't go a full gas tank with the see through one.

Hope this helps, Sean

taken19

That sucks. Could you install one for everyday driving and swap back for inspection purposes? It only takes about 10 minutes.

Thrash

It's really easy to pull the hoses off and if you put your own loop-hose that can come on and off easily (not using clips), that way a switch out would only take a minute ...

taken19

One additional thought. After a few months I noticed that the oil collection slowed down and thought it may be that cylindrical filter at the top. After drilling several angled 1/16" holes, the oil collection went back to "normal". I'm not sure if that made a difference or I just happened to change driving habits for a short period of time, but I though it may be worth mentioning.

Joe_G

Those compressed air filters are made to get water out of compressed air. They don't work long term for collecting oil mist.

I suggest you get a real catch can. I have an AMW, Tracey Lewis makes a good one with a real pcv valve. He has a great write up here.

http://forums.corvetteforum.com/c6-t...-catchcan.html

Don't dump that oil back in the crankcase. It's full of nasty stuff.

Gearhead Jim

I don't doubt your honesty, but I don't understand how you can be catching that much oil.

Oil consumption on our stock 2009 LS3 (no catch can) is so low that it's difficult to measure, would probably work out to one qt per 20k-24k miles. Many other people report similar numbers. So even if we had a system that caught all of the oil being used, it still wouldn't be catching as much as you are.

C7/Z06 Man

I installed one of these in my 2010 GS. Even with a few trips to the 1/4 mile track in 150 miles of driving I collected one teaspoon of oil in the cup which looks like a lot; but the math works out to be 1/2 QT. in 14,400 miles. So I would measure the amount your actually collecting to the miles traveled.

Dump the oil before it reaches the bottom of the so called filter which does not take long for me.

Edit: Go back and look at "taken19" pic of just the clear container and notice how big the end of his thumb looks compared to the container and/or oil in the container. PS: looks to me that these things are doing their job.

Joe_G

That level of consumption looks just about right to me. If you putter about town, you won't use much oil. If you race your car, or drive in a spirited manner, particularly with the engine at high revs, low load, thus high vacuum conditions, you'll draw up a lot of oil into the intake.

5 Liter Eater

I'd like to hear/see how you have it routed. That much in ~125 miles seems like alot.

PS: Do not re-use the oil.

NYC6

Do not pour it back into the crank case! It is oil heavily diluted with gasoline, H2O and sediment. Only fresh oil into the engine supply.

99c54me

I do not know or pretend to know the reason some LS engines have this problem and others don't. My present LS3 doe snot seem to use any oil at all that I can measure between oil changes. Prior LS engines I have owned did use oil, maybe 1 qt every 1,500 miles (more when driven spirited, less on the hwy.

Either way that top end lubrication excuse strikes me as BS and if I had an oil user again I would try to catch all I could.

There have been some good write ups on this. I have a co-worker that routed the back valve cover opening and merged it with the existing path, says he reduced oil usage a bunch. Theory was less suction in one path vs two reduced the bad effect. He found the suggestion on this awesome forum a coupe years ago.

Also there are some not so great write ups on this topic so keep your BS detector on at all times when reading.

HOXXOH

What makes this oil any different by being caught in a catch can, than any other oil in the engine?

If the rate collected is about 1/2 quart in 10K miles, where does the 5 quarts go in a 100K motor that never had a catch can?

taken19

The truth is that there may be no difference at all. The concern is that you could be putting bad (contaminated) oil back into the engine. It could have no effect or it could end up damaging the motor or accelerating the normal wear. But why would you take the risk for a few dollars of new oil? Is it worth risking potential damage to the motor? Not in my opinion.

The goal of this forum is to share ideas and best practices among fellow car enthusiasts. Readers should consider the information they read here and filter it for themselves when making decisions.

To answer your other question, the oil that the catch can does not collect goes into the intake manifold and the combustion chamber. This can cause carbon deposits and potential hot spots. I pulled my heads at 38k and couldn't believe the amount to carbon buildup without the catch can. Look at the pics I posted above to get an idea

HOXXOH

My point was that the oil caught is no more contaminated than all the rest of the oil in the engine. The system doesn't separate bad oil from good oil unless you consider that the oil first caught after an oil change is less contaminated than any subsequent catch as the entire oil fill progressively degrades.

I knew where the oil went, but was joking. I suspect the carbon in your engine was more the result of the gas you use and your driving habits. I pulled my heads at 71K and had almost no buildup and had not used a catch can.