Prius Gen 3 Major Maintenance: EGR, manifold, spark plugs, Oil Catch Can

Yeah that's a sand pounder for sure. Not sure how critical it is. Without it you might have slight leakage? And what does that do?

 

You should be throwing a leak code (that happened once to one Prius I cleaned the egr circuit on).

We didn’t snug the bolts on the back and it threw the gross leak code.

I’d think without the gasket, you’d have a similar thing.

Maybe not I guess .

 

I bet leaving out the gasket and missing the bolts are not the same It worked without it for a week, but I might be lucky.

 

I've been thinking about that gasket. Without it, you've got two stamped surfaces making the seal, not that good. With the gasket between them, each stamped flange contacts a thin, very flat and somewhat flexible surface. Maybe the gasket steel is a bit softer too? Plus everything is pretty close tolerance: without the gasket there's more resistance to draw the gap together??

Bottom line: the engineers thought a gasket was needed.

 

Anytime you’re mating two surfaces together, something softer than either helps ensure nothing leaks out.

Combustion gases are not something I would want in front of me while I’m driving.

I’d get a gasket and get it sorted.

 

If @capolihu takes the plunge, he should time it. About 4 hours? What a pain though.

Could coolant hoses be left on? msybe everything could be just loosened, and the rearmost bolts (or is it studs?) removed and the gasket slipped in?

 

You could probably slip it in.

What I do is get the e8 torx socket out and remove the stud. It should work.

Whatcha got to lose?

Worth a shot.

 

Yeah, I was also thinking, just loosening the bolts (after the windshield part of course), removing the two back and slip it under the table in a low low.. Maybe I find a place for my leftover bolt. I don't know where it belongs to I find the time next week when I feel I recovered from this last one..

 

Mostly yur back?

I did an oil change and tire rot. recently, on our daughter's Pilot, and my back went out before I even got started. To be fair, I think I was reaching 6 ton safety stands out from the work bench bottom shelf, probably did it. But it feels like my back goes out if I just look at her truck, lol.

 

Maybe if she got a Jeep your body would be more accepting .

At least your head anyway.

 

Hi guys,
I did almost all the same maintenance on my 2011 Prius @88k miles except the EGR cooler and spark plugs. Everything looked good until i started got a rough start and a engine light; then realising that the OCC hoses were incorrectly switched for the manifold/pcv and that the maf sensor wasn’t plugged in, I adjusted everything back in place and reset the check engine through disconnecting the white cable in the fuse box. Then i scanned the car at autozone for any codes. The check engine light wasn’t on but it still pulled some really weird codes (see attached) also i noticed a dip in mpg from ~45 to ~35. I thought this might be the computer remapping the new readings. I’ve driven about 50miles locally and do see it improve after it ‘warms up’ after about 2miles after cold start. But it still doesn’t seem to be as efficient as it was before. Everything seems to be running smoothly except for the strange efficiency and latent engine code issue. I’m really stumped, do you have any suggestions?

 

So you did this?

Basically the intake manifold side of things? Maybe a vacuum leak, somewhere in that OCC install? What did you clean the MAP and MAF sensors with?

 

Check and double check the electrical connections, like the MAF sensor connection at the top rear of the air filter housing.

 

Yes, I did all of those. Also the egr pipe, just not the cooler itself. I cleaned the sensors with crc maf cleaner. The map sensor was pretty foul and brown inside so i cleaned it a bunch.

I’m going to pull everything open again now that the holiday is over and check for any leaks. I opened the OCC to see if the steel sponge was too tight for airflow, so i cut it in half and loosened it more. One idea i thought of was that I used 2x 3ft hoses on it and didn’t trim them down so i have about 6in of hose looping around (not kinked though), do you think that it’s too far a distance for that air to travel? Since the original U shaped hose is really short.

The maf connector is solidly in, I’ll get down and check the map sensor when i tear down again.

 

Yeah it's debatable. My Moroso can has pretty dense packed steel mesh, one "wheatie" per (intake and exhaust) side, that's how it came:

I'm not sure. I think a longer length of hose imposes some flow reduction, but minor. You see a lot of installs with hoses snaking a long ways. If it's excessive I would trim them some. Fuel line is cheap and readily available, if you need to redo at some point.

 

I had longer lines on both my 2010 and my 2013 V catch cans and there were no difficulties.

 

So now after 506 miles the only code remaining is the P0102 mass airflow circuit low input; definitely worries me last time I got it, it led to a blown head gasket at 195k which I’m working on as well.

i am hearing some odd noises, a sort of whining sound when the defroster is on. Trying to sort this out but I don’t know why this code is on. I will clean the MAF sensor again but i don’t think that’s the reason.

I’m def changing the spark plugs next week.

 

wvs2003, thanks for the write up. I just acquired a 2010 Prius III with 155k miles on it. I'm going to do the exact same maintenance on mine, and I'm putting together a shopping list. Does anyone see anything missing?

• 25634-37030 EGR Tube Gasket
• 25627-37010 EGR Valve Gasket
• 25685-37010 EGR Pipe Gasket
  
• 17177-0T020 Manifold Gasket
  
• 4 x 90919-01275 Spark Plug
• 12204-37010 PCV Valve
• 12261-37060 PCV Hose
  
• Ruien Oil Catch Can
• 3/8" x 5 ft fuel line
• 5/8" hose clamps
• 3/8" ID hose barb
• Brakleen
• MAF Sensor Cleaner

Unfortunately I can't post links yet.

 

Maybe a jug or two of Toyota engine coolant. You could clamp off the coolant hoses or just drain it. If you drain coolant it means removing the belly pan and you might want a few spare plastic rivets on hand.

 

3/8" ID hose barb

See if you can get PEX splice instead of barb style. I got barb, that's all I could find, but they're a total pain if you ever want to pull the hose off, say to slide on a clamp, make a revision, whatever. What I end up doing is mounting the barb-style splices in a drill press, knocking the sharp edges off slightly, with a file.

12261-37060 PCV Hose

Why are you getting that? So you can restore the car to stock at trade-in time? I can see that, actually did the same.

Incidently: I did purchase that hose, for that reason. Full retail through local dealership, close to $20 CDN. And of course now I see this:



4 x 90919-01275 Spark Plug

Have the plugs not been done?

25634-37030 EGR Tube Gasket
25627-37010 EGR Valve Gasket
25685-37010 EGR Pipe Gasket
17177-0T020 Manifold Gasket

Not sure which is which, but I wouldn't bother getting the 3 metal gaskets, the ones between the one at junction of pipe/valve, valve/cooler and cooler/exhaust manifold. They're plain metal, pretty much bullet-proof. The last one is prone to being lost, having no clips: be ready to catch it once the studs are pulled out.

FWIW, I replaced no gaskets when I did ours at 70K kms, pretty early though. 155K miles is almost 3 times that?

Brakleen

Consider Oxi-Clean for the cooler too. Get powdered Oxi-Clean, mix it with hot tap water, as concentrated as possible, pour in (with lower ends plugged), let soak an hour, rinse and repeat. It'll take 5 or 6 sessions thus, to get it spotless, with the cooler. Oxi is also good on the intake manifold. Don't use Oxi on the (aluminum) EGR valve though. And have an assortment of corks, bristle brushes, and so on.

Ruien Oil Catch Can

Read the reviews. Not sure, but there is a spectrum of oil catch cans.

Don't disconnect the throttle body coolant lines, no need: just lift the throttle body off and tie to inverter or hood release.

For the EGR cooler, yeah you have to disconnect, but if you drain 2 quarts of coolant (at the radiator drain spigot) before starting, into a clean container, The coolant level will drop below the EGR, and you won't spill a drop. There will be a few tablespoons trapped at the lower/back corner of the EGR cooler: just lift it off and pour into the previous drain. Afterwards pour the coolant back into the reservoir.

Having a 2010, you have a coolant bleed valve atop the EGR: leave it open when pouring the coolant back, and shut it once coolant starts to come out. Also, burp the main hoses a bit (squeeze them) as you're pouring the coolant in. Level will be a bit high in the reservoir, should settle down in a day or two driving.