Oil Catch Can are useless

Generic amazon 350ml located under the engine. I take out the air filter box to dump it between oil changes, takes about 10 min. It wouldn't bother me if it filled up faster in the summer and not the winter. I suppose I could have located it up top and that would pretty much solve my issue.

 

Maybe that can just isn’t very effective; does it have internal baffling?

 

OMG. I just spit out my drink! ROFLMAO!.. My wife and I HAVE HEATED ARGUEMENTS OVER MY DIRTY SHOP TOWELS. after 13 years of marriage............we now have rules...
LOL. I now have my own stash that are MINE. We have a drawer full for the FAMILY to use..and SHE has HERS in a super secret stash somewhere in the woman cave. NO JOKE.

 

The wife and I came to a compromise a couple years ago, actually. I keep a cardboard box in the garage near the door that goes into the house/kitchen area. When she has any household towels that she deems no longer worthy of keeping (regardless of size or where used), she washes them one last time and then places them in that box, where they officially become shop rags. I have quite an abundant supply. Anywhere from beach towels to facecloths. I still like to grab one from the kitchen every now and then just to keep her guessing..

 

Correct. The Gen 3 intake manifold does a great job at catching oil, sludge, carbon, water, etc. In fact, it's so effective, it can completely defeat the EGR process, causing broken head gaskets and piston rods, etc.

 

It's hard to keep track of all the "x causes broken head gaskets and rods etc." stories floating around PriusChat. Some are less persuasive than others, but we might just have set a new record.

 

You are right. As noted above, more recent engine designs drain the condensate back to the sump. The condensate volume is much less in engines without low tension rings and a low PCV valve location.

 

Here is what I think. I stopped reading (and you should too) as soon as I saw so called Master certified technician said: I pulled the cooler off of my personal Prius with 130K and the unit was spotless.

 

This is a decent point. Why don't people just siphon out the oil from the intake every oil change instead of using an OCC. It's easy to do and easy to access.

 

What percent of the oil/gas/water delivered via the PCV is waylaid by the intake manifold? And how much passes right through?

I prefer opening the drain tap on an oil catch can to pulling the intake manifold. To be fair every few years I’ve been pulling them (dual Moroso 85474 cans in series) for cleaning their interiors.

 

I think this is not done because there's more than enough room and it getting too full has never been documented... Suspect all that air getting sucked thru their helps to keep it from getting that way.

 

That clickbait title and picture shows what's going on when there's a serious problem, like a blown head gasket.

I seem to be the odd guy here, in that I don't think of it as much of a problem. Yeah, it's nasty-looking, gunky, and messy. It also works to some degree like an oil bath air intake filter too. (This is what some cars, tractors, and other engines used to trap particulates in the engine intake pre 1950's).

With a Gen 3, I pull off the intake manifold when servicing the EGR - cleaning the throttle body and intake manifold along the way. Unless there's a serious problem with the engine, the intake manifold build up less than 1/8" of oil and crap. I just don't think that's enough to crawl up the inside of the intake manifold and work its way into the engine intake. I also change the PCV valve, just because I'm there too.

If it makes you feel better, yeah run a catch can. I just don't see where it's really that much of an improvement. Like I said, I seem to be in the minority here.

 

What's feeding into the intake manifold via the PCV hose is a fine mist. Short-sighted to think it all liquifies and condenses neatly at the bottom of the intake manifold? Maybe that portion is 50%? Less?

The gunk you clean out of the intake ports is oily; that's not from the EGR.

 

I may need glasses, but I'm not short-sighted in that way.

The oil and gunk I'm talking about pools in the bottom of the intake manifold underneath the throttle body. To me, this is the result of how the PCV system works. Yeah, it starts off in the crankcase as oil and water vapors, as well as piston ring blowby. I believe it can act as an oil bath air cleaner, trapping particulates as well as other things that make it through the air filter.

It is not from the EGR system. I never said that. it's from the PCV system. I only suggested that the oil and stuff doesn't build up that much if you clean it out when you regularly service the EGR, and that there may actually be a positive benefit from having a little oil at the bottom of the intake manifold.

 

And what Mendel was saying was that there's still oil in the actual intakes on the head, so the intake manifold isn't catching as much as it could. Therefore, the reason some of us add an OCC to the path between the PCV valve and the IM.

SM-G781V ?

 

That's like the so called "water saver" low flow for faucets and showers....
You NEVER "save" any water. If you need 1 qt of water, you don't save anything
by taking 1 minutes to get a qt verus 15 seconds.
So if you change your oil every 1000 miles, you'll never have to add any, thus it's not burning oil.

 

Where can I buy the best oil catch can setup?

 

I've heard of OCCs in forced induction / turbo engines, but on a Prius...idk. Removing oil where it doesn't belong is always good, but even if these Gen 3 PCV valves are located on the lower part of the engine...I don't see it being a huge issue vs. not running one. We still have clean the EGR anyway. I'll do without for another 60k and install an OCC if the EGR is super clogged again.

If you're in CA, high chance of failing the SMOG test with a catch can installed. If you're in colder climates, I'd be careful of letting oil/sludge clog the extra tubing that you're installing with the OCC during sub freezing temps.

Sometimes I question the need for minor preventives. I just cleaned the hybrid battery fan after 111k and sure, it was dirty....but the mass of the removed dust was so marginal that I highly doubt whether it was affecting the efficiency or drag of the fan. It was good to check and make sure it wasn't clogged, but in my case it was definite overkill.