Look At What Came Out Of My Catch Can

[Vinmega]

Brand new Yukon Denali. 6.2 motor.
This is after 1100 miles. I installed this and the truck had 14 miles on it.
I did first oil change today and went with 0w-40 Mobil1 Full Synthethic.
This is a JL brand seperator.

Check out how much this caught just after 1100 miles on a new motor.
Its like a half cup of Espresso.....

 

[89Suburban]

Should calm down once the piston rings seat themselves.

 

[Marky Dissod]

Without the catch can, your engine would be trying to burn that stuff, to varying degrees of success.
Have that stuff analyzed (preferably NOT by BlackStone), you'll learn why your engine will last longer.

Might even help others get why they should have one installed.

 

[viven44]

Ya that quantity is what the old big block in my truck would accumulate in 300 miles, with my oil burning progressively getting worse I was worried about blowby on this tired engine and I ran a catch can until last month, but I'd only get ~0.5oz (about what is pictured there) but magically burning through a quart (32 oz) every 300 miles. Sure enough it was the valve stem seals, so after I replaced them I got rid of the catch can. 1oz via PCV every 600 miles is nothing for an old school carbureted engine... now there are some other benefits... the oil vapors do reduce the octane rating of fuel, probably negligible ... eliminating or reducing that would be nice

In your case 0.5oz/1100 miles isn't bad at all, but these are GDI so better to be safe than sorry, if only I can get Mrs. to check and empty the catch can I'd install one in our 24'.... but that's not happening

 

[Joseph Garcia]

I log my catch can oil volumes, and I average about 1 fl. oz. of oil for every 1000 miles driven.

 

[Marky Dissod]

I log my catch can oil volumes, and I average about 1 fl. oz. of 'oil' for every 1000 miles driven.

The chemical difference between crankcase motor oil and what's in the catch can is why catch cans exist.
Otherwise, why not just pour what's in the catch can back into the crankcase?

DON'T DO THAT.

 

[jfoj]

Will try to get a measurement on mine, I have about 3000 miles on 5W30 and I think there is about 3/4" in the catch can at the momement. I drive about 80% on the highway, so this may generate far more pumping action in the crankcase and the oil temps tend to be higher.

As for the piston rings breaking in, they are broken in during Cold Testing at the factory. No longer hard chrome rings that take 1000 miles to break in. Cylinder bore finish and piston ring materials are so different from 30-40 years ago.

If you have a DI engine, a catch can is a wise idea.

All the European vehicles with factory oil separators drain the oil back into the crankcase. This makes the oil saparator pretty much no maintenace, or does not need to be emptied. But I agree, best to drain off what has been caught in the catch can into waste oil.