Oil Catch Can (aka Air-Oil Separator)?

Anyone done this on a 4th gen, or thinking about it? Strategies?

No time like the present.

 

Good point. I guess @danlatu 's thread is the main one:

Oil Catch Can, Eliminate that knock! | PriusChat

The main culprit seems to be airborne oil mist from the PCV valve, condensing/pooling in the intake manifold, and maybe getting sucked into the combustion chambers as well. This is something that's happening from the get go, maybe you can't be too soon? I've heard more that one comment about adding this right away, with a new vehicle.

 

Maybe you're thinking of the EGR improvements? Not sure. A relocation of the PCV valve, positioning higher up on the crankcase wall might help, or a better baffle system leading to the PCV valve connection. Not sure.

If you can get a look down the throat of the throttle body and see oil beyond, that would be a tip off to the need for an OCC.

 

Removal of intake manifold is likely the best approach. There's (as far as I know) a couple of hoses, if it's similar to 3rd gen.

One hose (the one you're maybe thinking of) goes from the valve cover to a spigot on the intake air snorkel, at a point between the air filter and the throttle body.

The other hose, and this is the trouble maker, runs between the Positive Crankcase Ventilation (PCV) valve (mounted high on the crankcase wall, below intake manifold), to a spigot on the side of the intake manifold, downstream from the throttle body.

An OCC is typically installed along that second hose.

 

Here's the hose between PCV valve and intake manifold on 3rd gen. Throttle body is mounting on Intake Manifold just to the left of left end of hose, PCV valve is screwed into crankcase on right end.



I ended up cutting that hose at the mid-point, rotating the two resultant "elbows" downward, and splicing in the oil catch can.

Best I can do btw, haven't got a 4. You might be able to see the PCV plumbing, by just removing the air intake snorkel and air filter box: the intake manifold looks very compact and high up.

 

This might be the hose on the 4th gen:



If not, it's likely in that mass of spaghetti, somewhere.

 

@danlatu has posted a picture of fourth gen PCV valve and hose in his OCC thread, looks to be very similar to third gen location.

Oil Catch Can, Eliminate that knock! | Page 16 | PriusChat

"12204" is the PCV valve, and "12261" is the hose.

 

A bunch of procrastinating grasshoppers, lolling in the summer meadow...

Pot calling the kettle black: it took me to 70K kms to wake up, but eight-o'clock-day-one is the optimum time to address this.

 

I got a scant tablespoon, if that, in the first 350 kms or so. My setup is pretty much only accessible from below, so it'll be spring oil change when I'll open the drain tap again, measure what comes out. I've got a wee jar that I've engraved with CC lines, will see what I get with 4~5K kms.

More telling, pull the throttle body again (or at least have a look through the throat), and see if it's stayed oil-free. I suspect besides the PCV, a slight amount is trickling down from the intake ports.