Oil separator purpose?

[JLUR2LT]

What is the purpose of the oil separator? Separate oil from what? What happens to the oil that gets "separated"?

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[58Willys]

Your crankcase needs a vent for when the piston travels down, so as not to pressurize the crankcase, and slow the piston down. Old vehicles just vented to the atmosphere. Since the ‘70’s, we’ve had PCV’s, positive crankcase ventilation, that routes the crankcase vapors back into the intakes to be reburnt, an emission thing. The oil separator separates the oil from the vapor, so theoretically the motor isn’t burning oil, just vapor.

 

[JLUR2LT]

Thanks.
It sounds like the same principal as an aftermarket "oil catch can"?
Does the oil separator need to be emptied of the oil it collects?
Or am I misunderstanding something?

 

[58Willys]

Depends on the style of separator. A catch can needs to be emptied, a PCV no.

 

[JLUR2LT]

Sorry, should have elaborated more in the first post.
In this case I'm refering to the Jeep factory installed oil separator mounted between the engine and engine bay firewall in Wranglers with the 2.0L Turbo engine.
In other threads of this 2.0L Turbo forum people mentioned their oil separator was leaking, along with rear main seal in some cases,.....
That is the specific oil separator I'm wondering about, where the oil goes after it is "separated", and if it requires some sort of maintanence over time like ever possibly needing to be emptied of the oil it's seemingly collecting.
And if it doesn't actually collect oil, then what exactly is its purpose?

 

[58Willys]

Hmmm. I looked in my factory service manual, and it doesn't give an explanation of where the oil flows to or from the separator. Do you know the flow pattern? In general, oil separators separate liquid oil, from oil vapors. I have a 3.6, so I don't have a great answer for you. Guessing it's either crankcase venting, or valve cover/rocker box venting. Hopefully someone smarter than myself will come along with an answer.

 

[JLUR2LT]

I don't know the flow pattern.

 

[Speed331]

One would assume the oil flows back into the pan. The placement on the lower part of the block would give it a simple pathway.

On a side note, it seems to be a very effective system, as all the posts I've seen from those who installed catch cans on the 2.0 report nothing but a smattering of oil in the can after significant milage - vs the V6's that fill the can quite quickly.

 

[Speed331]

It looks like a straight forward baffle system. The oil return system must be built into the block, as I see no connections on the outside of the unit. It looks like the air moves through the baffle from the right side of the image and is maybe vented out a connection at the front, while the oil collects in the larger reservoir and flows back into the block.
I've not seen it on the engine so I'm speculating.

 

[JLUR2LT]

Thanks for the info. It's more than I knew before.

 

[MrBill1963]

I believe it is send back through the intake to get burned, hence people installing catch can to stop the gunk being sent back.

 

[CptFloridaMan]

In my case I think mine gets sent out to atmosphere via dripping down the block lmfao. I have a photo somewhere that I can see one of the wire harnesses are saturated with oil. I've never seen it on a block though, but I'm trying to remember the one thread where he rebuilt a 2.0 and showed pictures of the open deck block back then when we were all speculating what kind block it had.

 

[CptFloridaMan]

Found it,

https://www.jlwranglerforums.com/fo...-main-bearing-where-to-buy.49119/post-1088019

https://www.jlwranglerforums.com/fo...-main-bearing-where-to-buy.49119/post-1102092

On the picture that is looking down onto the block, you can see the separator on the left side of the picture. So definitely not an easy spot to get to.

 

[JLUR2LT]

Well apparently a team of engineers thought this 2.0L Turbo engine needed an oil separator thingy, and apparently they did a pathetic job engineering the oil separator thingy, and apparently it's top secret why it's there.

After a handful of people in recent threads have pointed out how much the oil separators are leaking oil, in vehicles that aren't that old or with that high of mileage, I'm starting to think an oil separator delete is the best remedy. Maybe it's not that simple?

Is it possible the oil separator is part of the PCV setup? Can an oil catch can be mounted in place of it?

 

[CptFloridaMan]

Well apparently a team of engineers thought this 2.0L Turbo engine needed an oil separator thingy, and apparently they did a pathetic job engineering the oil separator thingy, and apparently it's top secret why it's there.

After a handful of people in recent threads have pointed out how much the oil separators are leaking oil, in vehicles that aren't that old or with that high of mileage, I'm starting to think an oil separator delete is the best remedy. Maybe it's not that simple?

Is it possible the oil separator is part of the PCV setup? Can an oil catch can be mounted in place of it?

I’m gonna piggy back on that question, if a catch can is mounted, will it reduce the amount of vapor/oil going into the stock oil separator?

Kinda had the thought yesterday but I believe the PCV system is built into the manifold as well.

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