Do I really need Oil Catch Can (OCC) in 2012 Prius?

I installed a Moroso OCC (model number 85682) in my 2010 around 135k miles. the car was probably burning about .8qt over 5k miles. the OCC was a top-based inlet and outlet system, with the holes facing down into the can; and a somewhat fine steel mesh insert in the top of lid. it was nothing like xliderider's fine mesh and there wasn't any steel wool in there either. over several tests, and oil changes, I found that the OCC didn't really catch more than 10-15% of the oil burned in the system over 5k miles. this gave me a few theories: 1. the OCC I was using kind of sucked and wouldn't condense oil well enough; or 2. oil was simple getting burned after leaking past the rings during runtime. I could never figure out which one it was. I tend to think it was the later as the crankcase air pressure is probably not that high, meaning not too much air/oil mist moving through the PCV circuit.

I almost question whether it was worth it to install the OCC, especially since in the winter, I would get mostly water accumulation, mixed with the minor amount of oil. and it would look like your picture - something like coffee diluted with a bunch of cream. I think after some time, the 10k OCI interval recommended by Toyota wreaks havoc on the rings, gumming them up, and then they kind of stick open, allowing oil to enter into combustion (car care nut on youtube). I thought at first that stuck rings would increase the crankcase pressure, but I think that's probably minimal.

 

Regarding intake manifolds, there are several revisions. In my 2010, I originally had the oldest revision (17120-37091 - I believe), and during an EGR cleaning, grabbed the newest used part number I could find (17120-37054). this is the one used, at a minimum, on late-model 2014's and 2015's. it fit in nicely and there were no issues after install. I don't think it really did anything significant like boost performance or reduce oil consumption, however. But at least I had a 2015 engine! LOL

 

I believe I went from the same intake manifold part number in our 2011 to the same one you got. Mine came from a Lexus CT200h.

Posted via the PriusChat mobile app.

 

this was a fascinating post, basic physics law should be applied, the hot gas coming in the can needs to be forced downward so it travels some distance in the can, expands, and cools down, a tube of fine mesh all the way down on the inlet ad outlet on the inside of the can should help.
also the longer 7.5" OCC marked 750ml should help with that. I am convinced that moving the PCV to the outlet of OCC is the way to go. have to decide how to implement it and where I can fit the longer OCC.

can the old PCV valve be drilled out and used as an open connector.
Does it matter if the connector used instead of PCV is stainless steel or brass?

Thank you to
@Prius DIY nut & @xliderider

 

The PCV valve is a "gatekeeper". Moving it further along the path between crankcase and intake manifold won't hurt, but I can't see it making an oil catch can any more effective. If you want frequent access to the PCV valve, say to clean or replace, them maybe.

Occam's Razor would govern for me: stick with the simplest approach, change a minimum of variables..

 

The PCV valve is a one-way valve, so putting it on the outlet of the OCC is backwards.

Edit: disregard above it's incorrect, it's still early in the morning lol.

Unless, you are using the OCC like me and using the stamped outlet as an "inlet".

Regarding the replacement for the original PCV valve on the engine. The aluminum OCC adapters are usually the correct size and thread pitch to just screw in place of the original PCV valve. Use the one that fits your tubing.

SM-G781V ?

 

Outlet of OCC is no different than outlet of engine where it normally sits. It's just that now you're filtering before the PCV instead of after. There is no backwards unless you flip the PCV around, then you have a problem.

 

Yes, I realized that after I posted it. That's why I inserted the "Edit" comment, rather than deleting it.

I guess it could be confusing.

SM-G781V ?