Oil Catch Can, Eliminate that knock!

Thank you Mendel for taking the time to reply. I find it odd that during the summer cycle the first can accumulates more fluid, whereas during the winter cycle, the second can tends to accumulate more... I'm rather confused, not sure what sequence should I choose for mounting mines in series... Maybe I will stick to a single catch can, the bigger and supposedly more efficient one, which also comes with a drain valve.
As concerns the front beam mounting point, you already made it clear it should be somewhat elastic to allow the beam to flex, you mentioned this several times, it's noted
Another thing that's on my mind is the importance of connection size to/from the OCC. As I see it, the gases mixed with liquid droplets have higher velocity in the small section of the tubing and they tend to slow down in the larger section of the OCC, thus increasing the residence time and the chances for the liquid phase to condensate. To extend this effect I would like to use a larger diameter of hose from the OCC to IM, actually keep the IM size. Is my reasoning coherent?...

 

I used 3/8” ID fuel line, and cut the OEM hose at the middle, spliced into it at the ends, per @danlatu did, at the outset of this thread. The hose to the intake manifold has to turn 90 degrees promptly to avoid running into stuff, a factor to consider.

 

I am familiar with your setup. Thanks for the tip about the narrow space under the IM, where the OCC connects, it was not very fresh in my memory. Maybe use 16mm hose and 90° splicer up there?... in conjuction with 16mm hose and hose barb to the OCC outlet, of course. (Edited the size with the correct ones in mm).

 

I replumbed everything one time with larger diameter hose (1/2” ID IIRC), and replaced all the brass elbows on the Moroso cans to match.

My worry being 3/8” ID, coupled with the additional length and increase in pinch points from all the connections was throttling the PCV flow too much.

It all worked, but was more crowded, and I finally gave my head a shake and went back to 3/8” ID and @danlatu recipe. Without clamps except at the cut OEM hose ends (per pic). It seems fine; I suspect my concerns about throttling were overblown.

 

Thanks for the feedback.

 

Very likely. In moderation, additional throttling might be a good thing.

 

Anybody here do their full synthetic oil? Do you change it at 5,000 miles or longer?

my car has 172,000 miles and oil looks fine at 5,000. I do have oil catch can which has caught a lot of impurities and what not.

any tips would be greatly appreciated

 

Some people here say their oil turn dark after a few hundred miles. If that’s the measurement then a lot of people here Prius is in big trouble.

 

It’ll look pretty good on dipstick, black as ink in a jar. With a typical gasser it’ll look black as ink on the dipstick.

 

I think I’ll do my oil change intervals at 8K instead of 10K miles. I was doing it at 5K but oil looks fine now and I’ve been reading a lot of the Toyota recommendations and other people talk about 10K being normal.

My oil catch can has been working great also, I noticed a lot of buildup so I used some carb cleaner last week. My commute to work is 60 miles round trip *every day*

 

I replaced my OCC yesterday with another version, which is a Chinese Mishimoto copy, the only difference being the taller reservoir. I'll post some pics. Quality is decent. The main reason I decided to change the previous setup, that used a cyclonic separator coupled with an OCC used only as a receptacle, was the higher capacity of the new OCC and the bottom drain valve. At the same time, the old setup still allowed some oil into the intake manifold, so I thought to myself that the sintered brass filter together with the baffles and taller reservoir of the new OCC will do a better job. I also used some stainless steel shavings scrub inside to serve as an additional condensation surface and to prevent the content from slushing too much.

So I followed Mendel's location idea and I drilled 2 holes in the top of the front beam, inserted self-tapping 6 mm nuts and secured in place a L slotted profile to support the OCC. I sandwiched a rubber (EPDM) gasket between the front beam and the L profile, as he recommended. I used the old hose cut in half to connect the OCC to the PCV valve and intake manifold, respectively.

A few observations from my experience>
- I hope this location of the OCC will facilitate the draining from PCV valve (and protect it from being filled with gunk coming back from the hose) and at the same time will make it difficult for the liquid to climb up to the intake manifold. I think it might be a better choice than somewhere in the upper engine bay area from this point of view.
- I could feel some resistance (not much, though) when sucking air through the OUT port of the OCC, most probably due to the sintered brass filter. I think this is the "throttling" effect mentioned by Mendel when worrying about kinks in the hoses (am I right?), but I hope it-s gonna be fine, as per CR94.

- I don't think I could have managed to fit hoses larger than 3/8 ID, the room under the intake manifold is pretty crowded.
- I still worry about the liquid freezing in the sintered brass filter, but I hope the second vent on top of the engine will work as a safety relief valve for the crank case pressure until the blockage melts in the OCC. To test this, I started the car and went shopping early this morning at - 8 degrees Celsius. Everything went fine.
- I cleaned the throttle body and dried the oil in the lower part of the intake manifold to have a good reference point regarding the efficiency of the new OCC. Next check will be with the oil change in about a month or so.
- Installed a short piece of hose to the OCC drain valve to make things easier later.
I hope my experience helps.

 

Don't overlook my phrase "in moderation," though. You don't want the filter to be (or become in use) so restrictive that blowby gas is forced to escape by an alternate route. Rightly or not, Toyota apparently felt the PCV valve alone provides optimum restriction.

 

It felt like a moderate restriction.
There are plenty of OCCs with such 50 micron filters in use and they do just fine, as far as I noticed during my research. Hope mine will, too.

 

I just want to throw out there...

If you live in a cold climate, I would recommend to NOT install an oil catch can once the season starts getting colder. Or drain it EVERY TIME you drive the car and park. I had an easy accessible drain valve on mine and drained it EVERY time but still had moisture carry-over into the manifold.
IF you have your catch can mounted ABOVE the original PCV port on the engine block (as I did mine), and the further away from the original PCV and intake manifold port, the more likely the hot, oil/oily air is to mix with condensing moisture, and will send that gravy-looking mixture into the intake manifold. This isn't really an issue if you live in warmer climates.

The best way to try to avoid this would be to mount the catch can BELOW the intake and engine block PCV ports (and still drain very frequently).

ALSO:
Performing the technical service bulletin to update the intake manifold (update to p/n 17120-37054, assy 17120-37091) to eliminate the cold start up knock, has eliminated my cold start knock.

The main difference is the throttle body gasket now has a mesh to create more air turbulence / tumble on the incoming air into the intake manifold and thus create a better mixture with the oily gases from the PCV valve as it enters the intake ports, preventing the oil from pooling up in bottom of the manifold. Upon my thorough visual inspection, I can't confirm what other differences there are, but it didn't look like much.

I have not had a single knock since, running WITHOUT an oil catch can. After about 1100 miles, I took everything back apart to inspect for any pooling oil. While I did have some oil (about 1/4-1/3 tsp), the engine still has not knocked since. Again, mid-west winters (Iowa), driven approximately 1100 miles (in the winter). No knock. No catch can. Car does not burn a lick of oil.

Just some food for thought.

 

What’s the miles and has EGR system been cleaned?

 

Miles is 218k miles. I've owned the car since 153k. Car does not burn a drop of oil.

At 153.7K, I installed my oil catch can. As stated above, during this time I would still sporadically have oil pool up in the intake manifold and experience start-up knocks here and there. I'd clean it out. During the winter especially, I'd have the oil-gravy carry over. During cooler months (starting in Fall), I would drain the catch can every time I parked the car. Pool up and knocks still eventually occurred. It wasn't so bad when it was consistently warm out, but I'd still have oil pool up sometimes.

At 160k miles, EGR cooler was replaced with new Toyota unit, rest of the system cleaned. This was done in Summer.

At 216.5k miles, I performed the intake manifold TSB and installed the new one (and removed oil catch can). This was also done during midwest winter. I have not had a single knock since.

At 217k miles, EGR system has just been serviced (again). I replaced both cooler AND valve with brand new Toyota units. I only had to change just the valve and I decided to do the cooler, too, since you have to remove it anyway for the valve.
The cooler I removed had little to no clogging (~57k miles on it) and I could still see light through it. But for the cost of $200 for the cooler, it's low enough cost to me I'd rather just buy a new one and replace it (I didn't want to wait for cleaning). This was done during midwest winter.

 

A lot of people here leaning towards replacement. They're eminently cleanable though.

 

Yeah, I didn't want to wait for cleaning and I wanted to install it right away. I'll keep the one I removed as a spare and clean that one, though.

 

Did you keep the coolers you replaced?
You can clean them out and use them again.

 

Timing helps.

Last time around (just this fall) I got the cooler out first, and had it soaking in the sink, set a timer for an hour. Then got going on the intake manifold, cleaning the EGR valve and pipe, and the PCV valve. Every hour or so I'd revisit the cooler, rinse it out and reload with fresh oxi solution. Net result, no waiting around, cooler was sparkling by the time I was ready to reinstall.

To be fair, this is the second time I've done this, and it was not that dirty.