ok, what the heck is a Oil Separator?

[midnight20pro]

Just stumbled on this: https://www.jlttruecoldair.com/jlt-3-0-oil-separator-2016-2020-toyota-tacoma-3-5l/

Says its more useful for forced induction vehicles, but I can't make sense of this:

During the process of venting crankcase pressure back through your intake track, large amounts of oil in the form of vapors can coat your blower rotors, intake valves, intercooler fins, and even dilute your gas lowering its octane level. This happens on all engines and is even worse when supercharged and turbocharged as crankcase pressures are increased. To combat this, we have developed an oil separator of our own design. Milled from solid billet aluminum this is a rock-solid piece. It has a knurled tank base for easy removal to drain the spent oil and an O-ring seal to prevent any leaks.

Is there really so much oil in vapor form going to the air intake side of the engine? Is this similar (identical?) to folks putting oil filters / breathers on import cars and bypassing the breather line to the intake?

 

[jchooley13]

Not sure about the oil vapor in naturally aspirated engines. I know it can get pretty bad in turbo engines. Even with an air oil separator the intercooler in my subaru gets a lot of oil in it. But it looks like what your looking at is more of a catch can than a "separater". Which is better.

Catch cans are more efficient at separating but the need emptied every now and then.

 

[midnight20pro]

Yeah I could understand under forced induction how you would end up with way more oil than you'd like in there I just wasn't sure if this is something a NA motor / owner needs to concern themselves with.

 

[jchooley13]

Probably once you start getting into the high mileage range. Once gaskets, o rings and normal wear and tear oil will start finding it's way into places it shouldn't be.

 

[NukedTaco]

If you google catch can you will probably find a lot of info. I think the benefits are pretty controversial.

 

[midnight20pro]

If you google catch can you will probably find a lot of info. I think the benefits are pretty controversial.

What's the controversy? Back in high school some would vent oil gasses to a filter instead of recirculating it through the engine, others might run a catch can. Curious what you'd consider controversy? I think preventing oil even in gaseous form from entering the intake side of the engine cycle seems like a positive to me. but I'm here to learn, so by all means let me know what you think.

 

[NukedTaco]

I think the controversy is whether or not they are actually beneficial. I can't say I'm really too knowledgeable on the subject but I think one side of the argument is what you stated and the other side being that the engine design already accounts for the oil fumes and the catch can does nothing to improve engine longevity or performance.

 

[midnight20pro]

Got it. Thx for clarifying

 

[nickyreno]

I'd get one. See bottom of first post.

https://webcache.googleusercontent....stall-guide.231227/+&cd=1&hl=en&ct=clnk&gl=us

I'm getting one based the logic that it can't hurt but it may help.

 

[WarFabArmor]

Not sure about the oil vapor in naturally aspirated engines. I know it can get pretty bad in turbo engines. Even with an air oil separator the intercooler in my subaru gets a lot of oil in it. But it looks like what your looking at is more of a catch can than a "separater". Which is better.

Catch cans are more efficient at separating but the need emptied every now and then.

This is what I was thinking as well looking at that. Catch cans are likely going to get more popular on the 3rd gens as more people deal with them. We installed one this year. Amazing how much you actually trap in them - Ill happily keep that out of the intake side.

 

[Lord Humongous]

I installed one a couple years ago. It was an easy, relatively cheap install and there hasn't been any I'll effects. It has definitely prevented some crude from recirculating back in the intake.

I'll share a quick story. After a full day of towing in some heavy rain I noticed a slight odor of oil in the cab. I never flipped the ram on my snorkel backwards to prevent water intake plus the engine was running slightly higher rpm due to increased workload. I checked the catch can and it was completely full of water with a little bit of oil. The odor came when it started overflowing. I'm glad that water didnt make it back into the motor for another go lol.

There is also some talk it may prevent the engine smoking situation on steep inclines.

 

[WarFabArmor]

There is also some talk it may prevent the engine smoking situation on steep inclines.

This is a big reason we did ours. Definitely be able to give some feedback on that in about a month

 

[Lord Humongous]

This is a big reason we did ours. Definitely be able to give some feedback on that in about a month

Awesome. I look forward to hearing about it. I'm curious if there will be measurable oil in the can after an incline? Maybe something similar to a small trap you'd see on sink plumbing would allow for vapor circulation but would redirect oil back into the crankcase once level?

 

[Spock]

There is a benefit on some direct injection (DI) engines. Since there is no fuel from a traditional injector to wash the backside of the intake valve in a direct injection motor, oil vapor builds up as carbon in the inlet path. Left alone for long enough this will cause poor performance and hard start. Using a catch can reduces the oil in the intake stream and thus reducing the carbon deposits.

I say “some” DI engines because in my experience with VWs CPRA/CPKA engines, the carbon buildup was not much of an issue. However with the previous gen 1.8t (whatever the code is) had a severe carbon problem that could cause a no start as soon as 70k