Is this a transaxle breather plug? (see photo)

You're probably right. There's only one of those and it looks like you found it.

Soot doesn't normally billow out of the transmission. You could have a major transmission problem. Or you could just be driving in a sooty environment or have an exhaust leak.

Pixel XL ?

 

It's probably soot from the EGR system when you removed it.
I think it is a breather for the transmission. If it's not vented, the heat will build up pressure and possibly blow
out of the seals. Which would not be good.

 

All looks like road grime to me.

Now how does your cooler look inside?

Good luck and keep us posted .

 

That basket is interesting; wonder what it's for.

 

It's good for keeping the robin eggs out of the engine this time of year.

 

Is it the 12 o'clock side of the throttle blade that pushes down? Trying to remember.

Maybe that grid is heated?

Revised Prius intake - Automotive Service Professional

https://static.nhtsa.gov/odi/tsbs/2016/SB-10084369-5448.pdf

@wheezyglider is your new manifold part no.: 17120-37054, per the above TSB?

 

Very interesting, thanks. So you think that grid is a heater eh?

By-the-bye:

I use a full feature text editor*, and keep a catch-all file, basically a text format "scrap book" of any-and-all, and gems like you posted go in there, like this:

====
Tuesday, April 9, 2019

Priuschat info regarding latest 3rd gen intake manifold:

Location:

Is this a transaxle breather plug? (see photo) | PriusChat

Yes, but it gets fun: I had looked at a similar TSB here on PC that specified part 17120-37091 as the latest replacement, so I ordered that. And the box it came in says 17120-37091. But the actual manifold has 17120-37054 printed on it. So warehouse change up? Or is the "manifold assembly" 17120-37091 actually made up of manifold 17120-37054 plus this arctic weather tweak?

At any rate, toyota.com parts catalog does show the 17120-37054 manifold as being the current thing for my VIN. (And BTW the one I replaced was 17120-37050.)
===

* Info on the editor:

TextPad - the text editor for Windows

 

Steps 29 through 36 above, I suspect Toyota is trying to avoid tensions building up as the cooler, valve and pipe are connected to each other and to the engine, exhaust manifold and intake manifold. Still @NutzAboutBolts just:

1. Bolts cooler and valve together.
2. Bolts above assembly to exhaust manifold and engine.
3. Bolts pipe to valve and intake manifold.

Both during removal and reassembly, it seemed to me the upper and frontmost stud on the valve was fighting, difficult to remove and install. This could be consequence of not following the Toyota procedure? @NutzAboutBolts noted the same "fighting", in his video.

I'd suspect they're assembling them at the factory per steps 1 through 3 above, and maybe that's why? Bottom line, I just could not fathom all the temporary tightening and loosening in steps 29 through 36, and doing steps 1 through 3, you manage to muddle through.

Then there's @Ragingfit's install: 3rd gen EGR on 4th gen engine. It free spans, from the exhaust connection to the intake manifold.

Yeah take a look at TextPad. It's free to download and try, and as far as I know if you haven't shelled out the 20 pounds or whatever it is these days, there's just a 4~5 second display of the TextPad logo at start up. Things that come to mind that it can do, and I'm just scratching the surface:

1. Wrap text that has hard returns at line ends.
2. Put hard returns at the ends of lines of text that's currently wrapped.
3. Change case, either all upper, all lower, first letter up and rest lower, or first lower lower and rest upper. Don't think the latter would ever be useful.
4. Insert system date by invoking a hotkey.
5. Same thing for time.
6. Sort text lines, alpha/numerically.
7. Use "regular expressions", ie page breaks, carriage returns and so on.
8. Search/replace

 

I don't think that the soot is from exhaust or anything. The breather plug's purpose is to balance the pressure insire the transaxle. This can be done by realeasing the pressure in both directions. Wear a mask for a day and go on the street; by end of the day, the white mask has captured enough particles that it has shades of black. Now dod the same for the age of the car, and tou will see how dark it looks after years. The plug is in an environment that sees q lot of things past the radiator lol. I wouldn't be worried about it since the pressure gradually changes inside the transaxle, so air will get in an out no problem. I took a picture of my 2015 with 72K miles on it. But if you want to spend the money, go for it. I bet it will look the same within a year Please send us an update with a picture after the installation.

BTW, if anyone wants to service this, its EZ to access it from the top.

Posted via the PriusChat mobile app.

 

More info for the group: I have a 2010 prius that I'm scheming to do a EGR clean/replace on. I know its got the old manifold part number, and i hate cleaning; so I called a toyo dealer here in PDX and asked the about 17120-37091. they quoted me $349. I said what prius does this fit in, and they could not answer. I then gave them my VIN and asked what manifold part number goes with my car. They quote me the 17120-37054 part for $349. Still looking, but im leaning toward the 17120-37054 piece now. BTW... the part from online toyo dealers is around $210 - just need to hunt around.

 

Cleaning the manifold is easy, takes 1/2 hour, with rags, brushes and a little brake cleaner.

I’d speculate the less convoluted passages on the old style are actually easier to access and clean. The new style was supposed to “cure” the clogging problem, well maybe make the clogging more uniform?

Who knows. At any rate, Toyota seems to have stopped touting the revised intake manifold as a panacea now.

The one thing that does work, is cleaning.

 

The T-SB-0103-12 Rev2 just happened to get discussed here in another thread just a few days ago. It does give 17120-37091 as the manifold to use. (On the other hand, if you do a search on parts.toyota.com for a 2010 Prius, you still come up with -37054.)

Any time a revised manifold is mentioned, Mendel is likely to think it has something to do with EGR clogging, or wonder what the point is if it doesn't have to do with EGR clogging, because Mendel has a hammer and therefore things either look like nails or are of no interest.

But the TSB that recommends this manifold isn't talking about knocking noises or clogging, it is talking about P2111 throttle actuator codes and about the engine failing to start at low temperatures after cold soaking.

It seems like there can be multiple subtle effects that the engineers designing these manifolds have to deal with.

Even as far as the EGR passages are concerned, I'm pretty sure I read one Toyota analysis somewhere that was concerned in particular with how the passages collect water. One very plentiful component of exhaust gas is H₂O, normally as vapor, but after cooling down it is water, and one time I took my EGR pipe off for cleaning I did pour a fair amount of clear water out.

It seemed that at least one of the passage redesigns was hoping to reduce the effect of slurping that water right into the cylinders the moment the EGR valve first opens. (Right at startup, the valve should be closed, and there should be no flow of gas to make any slurping happen. But if for any reason the valve hasn't completely closed for startup, the water can be slurped right then too.)

While it looks like a simple part, it seems pretty much every element of its shape has been worked out through balancing a lot of different considerations.

 

thx chapman and Mendel for replies. regarding cleaning, I've never done it and was hesitant because the passages look hard to reach for the manifold. the cooler looks easy with a pressure washer and the EGR valve was replaced by the dealer in 2018 per a prior TSB. ill probably tackle this sometime in late October, but probably get the new manifold part for kicks and see what it does to my MPG. if it turns out easy to clean, I may just go that route too. I have a cheap endoscope and will check it out as deep as I can go.

 

Supposedly it's easy to clean a cooler with a pressure washer.

It's getting the cooler to the pressure washer that has you spending a day crawling around the car getting the wipers and cowl out and the coolant (at least partially) drained and a bunch of fasteners you can barely reach unfastened and then all of it reassembled again and refilled and burped and tested.

The intake manifold, by contrast, like twenty minutes, out and in.

It also makes a difference what your standards for unclogging are.

Some posts sound as if people are dedicated to getting their manifold clean enough to host very small state dinners in.

I took some flexible nylon tubing I happened to have around, and used it to knock a bunch of the carbon out the passages, and blew the crud out, and put the manifold back on. I have other projects.