1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Do all Gen 3's (2010-2014) need EGR Cleaning?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by PriusII&C, Jan 29, 2021.

  1. PriusII&C

    PriusII&C Active Member

    Joined:
    Oct 15, 2013
    370
    127
    0
    Location:
    San Jose, California
    Vehicle:
    2012 Prius
    Model:
    II
    Based on many discussions on PC, early Gen 3 model (2010-2014) tends to have excessive oil consumption, intake manifold oil collection, EGR valve/pipes/cooler clogging, which can lead to engine misfiring, and eventually cylinder head gasket blown. One of the preventive measures is to clean intake manifold and EGR circuit, replace PCV valve, and install an OCC.

    Since many of you are very knowledgable in this area, I'd like to know how often this cleaning should be done? Should it be done when an engine starts showing the sign of oil consumption, or should it be done before?

    My 2012 has over 110k miles. I am thinking about whether I should get all the cleaning done when I replace my spark plugs at 120k. BTW, my car did not show signs of oil consumption in the last oil change.
     
  2. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    7,610
    4,464
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    There is no Toyota service interval. Many suggest 100k miles, some think 50k miles. I can tell you that mine was replaced with new egr cooler (dealer parts and labor $800) and it was mostly plugged 50k later. In your case it means now and I would have the spark plugs changed at the same time since some of the work is the same.
     
    #2 rjparker, Jan 29, 2021
    Last edited: Jan 29, 2021
    scona likes this.
  3. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
    6,114
    4,040
    1
    Location:
    Wilkes Land
    Vehicle:
    2012 Prius
    Model:
    Four
    How long do you plan to keep it? And for how many more miles? If no more than a few years or 50,000 miles, just pass the task on to an uninformed & innocent buyer like the rest here does.
     
    Paladain55 likes this.
  4. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,796
    48,995
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    not all need it, but all need to be checked. i'm thinking around 60k, then depending on the amount of clogging, an interval based on that.
     
    scona likes this.
  5. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,723
    38,253
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    I’d say every 50k miles is optimum. 100k you’ll maybe get away with it, but this clogging doesn’t lay dormant, suddenly rear up at 100k. It’s gradual, and causing your engine to run hotter the more it clogs. And it concentrates the clogging on cylinder one first. So yeah, every 50k is prudent, my 2 cents. And clean the FULL circuit, including the intake manifold, or it’s all for naught.

    A tip: don’t reinstall the lower bracket hold-down nut on the cooler. You can remove the stud there as well. That’ll make the next time MUCH easier.

    Also, when you say “I should get it done”, is that dealership, third-party mechanic or DIY. I’d heartedly recommend the latter.


    Also, in one breath you say “all” 3rd gen, and the next you say “2010~2014”. I’d go with that first one.

    More info:

    Bad Flywheel | PriusChat
     
    #5 Mendel Leisk, Jan 29, 2021
    Last edited: Jan 29, 2021
    scona likes this.
  6. PriusII&C

    PriusII&C Active Member

    Joined:
    Oct 15, 2013
    370
    127
    0
    Location:
    San Jose, California
    Vehicle:
    2012 Prius
    Model:
    II
    Thank you all for the input. I plan to DIY (DIM?). Regarding the title of this thread, I meant for model Gen 3 year 2010 to 2014. I thought the EGR clogging was mainly a result of oil burning. Since Toyota is supposed to have fixed the oil burning issue with new pistons (including rings), it might be not an issue for year 2015 and later. It looks like the cleaning should be done for all Gen-3, regardless of the year of build.

    BTW, the tool list and tips are very handy and informative.
     
    scona and Mendel Leisk like this.
  7. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,323
    15,110
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    If you are the sort of corn flake who likes to schedule car projects according to their urgency, you can use a scan tool to ask the car for its most recent EGR flow test result.

    That doesn't just give you the pass/fail, it gives you the quantitative result and how far it is from pass/fail, so you can make your own call. This is one of the things the car automatically monitors in case you live in a place where emission inspections happen.

    If you have any concern about how current the result shown is, you can do a trouble code clear (this works even if there are no trouble codes). That resets all the emission monitors to "not ready", and you drive around for a while until they are ready again, and then when you ask for the result you know it's pretty recent.

    Of course if you do live in a place where inspections happen, you might not want to reset your monitors to "not ready" too close before your inspection is due.
     
    Tretor likes this.
  8. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,723
    38,253
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Somebody has to ask: what the heck is a corn flake?
     
  9. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,323
    15,110
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    It makes a better figger of speech when nobody, actually, really centers that question.
     
  10. nillyaway

    nillyaway Junior Member

    Joined:
    Jul 22, 2020
    6
    2
    0
    Location:
    Texas
    Vehicle:
    2012 Prius
    Model:
    Two
    I have only done cleaning on the egr valve and cooler cleaning but I think its best not to do all the preventive maintenance at a time. People on here tend to say hey if you take this part off then why not do x + y + z. It can save a little time if you it this way but it can be a headache if something was not done correctly and you need to backtrack and figure out what you did or didnt do in the process. 2 days after cleaning the egr cooler I drained my engine coolant. When I opened the bottom engine splash guard I found a nut that came from one of the egr coolant strut lol.
     
  11. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,323
    15,110
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    A wise point. The medical profession has the word 'iatrogenesis' for talking about the risk of causing new complications in the process of doing stuff. We don't use the word as much in mechanical work, but it's still something to think about.
     
  12. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,723
    38,253
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Maybe due to spillage during the EGR cleaning? FWIW, here's a fairly "surgical" method, that avoids coolant loss as much as possible:

    1. If taking off the throttle body (in order to remove the intake manifold), leave it's coolant hoses attached. They have more than enough play that you can clean it, and securely tie it to something adjacent, say the conduit on left side of inverter.

    2. Coolant hoses do need to be pulled off the EGR cooler when removing it, but draining a couple of quarts of coolant from the raidator beforehand, the cooler will be largely high-and-dry. There will only be a few tablespoons of coolant remaining, trapped at the back corner low spot. When everything is reassembled, open the coolant bleed bolt*, push on a clear hose (just to avoid spillage), and pour the drained coolant back into the reservoir. Burp the main coolant hoses as you go. When coolant starts coming out of the vent* close it and carry on. I found the coolant level ended up slightly high, and settled back down with a few days driving, without further intervention.

    * For 2012 model year onward Toyota nixed the bleed bolt, not sure why, cost saving?? Anyway, I'd think if you pull off one topmost hose, it would achieve the same function.

    I'd recommend to have the front end off and splash guard off, during the EGR removal/cleaning. You might want to temorarily lower it back down (with shield off), just so it's not so much of a "climb" to get at things. But for some steps access from below might be easier. And recovery of dropped stuff, naturally.
     
  13. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
    6,114
    4,040
    1
    Location:
    Wilkes Land
    Vehicle:
    2012 Prius
    Model:
    Four
    Things you pee on metaphorically when you are the messenger of not so pleasant news?
     
  14. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,723
    38,253
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Oh wait a sec, you quoted me saying just that, in your sig quotes lol.
     
  15. John TK

    John TK New Member

    Joined:
    Sep 30, 2022
    1
    0
    0
    Location:
    Cupertino
    Vehicle:
    2014 Prius Plug-in
    Model:
    Plug-in Base
    My 2014 Prius plug-in is at 150K miles, not showing sign of oil burning. Not sure if I need to check my EGR valve?
    From the picture , my engine layout is slightly different to the none plug-in version. So I don't know if it have the same issue.
     
  16. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    7,610
    4,464
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    Depends on your vin. After a certain vin you may have the improved pistons and rings. Which is important because they vastly limit the hydrocarbons flowing through the exhaust and into the egr cooler. Revised pistons and rings also slow down blowby that enters the intake manifold via the pcv valve.

    While it is true the egr and pcv systems were a design fail on gen3s, limiting oil and combustion blowby in those systems has more to do with carbon accumulations than preemptive and presumptive removals and cleaning. Same goes for catch cans. Carbon accumulations on engines from 2010- mid 2014 does not stop simply because someone improved the flow in the egr system at 100k miles. The low tension rings and pistons with poor oil passages are still in there doing their thing clogging up the whole top end twice as fast since they are worn. As stated above, my egr took 100k miles to clog the first time and only 50k the second time. Resolving the root cause is always the best plan; attacking the symptoms just gives the diyer warm fuzzies.

    The theory that cleaning prevents head gaskets has proven false many times but the claim still circulates on Priuschat and nowhere else, especially not with professional Toyota mechanics.

    On the other hand, in a 2014 you could have the bad rings from the factory, so why not go with cleanliness is next to godliness and who does not want to be next to Aaron Rodgers. Just don't drink too much of the psychedelic koolaid he suggests or think cleaning egrs on 2010- mid 2014 Prii is some sort of magic bullet.

    Updated pistons and rings in 2014 Prii. Use last six digits
    Prius 2014 Vin Production Change.jpg
     
    Foxglove likes this.
  17. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,323
    15,110
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    If you'd like to know how the EGR is flowing, go ahead and ask the car, it'll tell you.

    If nobody has looked at the condition of the four small EGR passages in the intake manifold, I would recommend a quick inspection limited to that, which is much easier than the full EGR adventure. The car's monitor for overall EGR flow can't catch differences between these four passages when they clog.

    We are recently learning of a way the EGR valve actuator can go bad, which seems, regrettably, to be another thing worth checking. It will show up in the overall flow result, though, so if you are showing a good result there, you can kind of relax.

    For a bit of perspective, going back to 1979 and my first experience with a car using EGR, I've never seen an EGR system that didn't need attention from time to time. The old ones could need reaming more than yearly, and I had a 1984 where the valve actuator would go bad about that often. I've had to work on my 2010's, so far, once. :)
     
  18. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,723
    38,253
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    I would, soon. See first link in my signature.

    what year’s @ASRDogman’s? He’s around 350k miles, periodically cleaning the EGR, head gasket ok.

    You can check your VIN against the attached, will verify your piston ring type.

    No oil consumption by 150K is good. How often are you changing your oil?
     

    Attached Files:

    #18 Mendel Leisk, Sep 30, 2022
    Last edited: Sep 30, 2022
  19. Nick Seifert

    Nick Seifert Junior Member

    Joined:
    Sep 1, 2019
    29
    8
    0
    Location:
    Vt
    Vehicle:
    2012 Prius Plug-in
    Model:
    Five
    I thought i'd add my own experience with my 2012 Plug in Prius, 160k miles on the odometer. I purchased the car used with around 80k miles on it, decent service records, but the EGR system was not on the list of repairs AFAIK. Knowing the issues and failures a clogged EGR system has caused in many Gen 3's, i figured mine was far overdue. Before undertaking this work, i did check that the EGR valve TSB (T-SB-0027-16) sticker was not present under the hood, and i confirmed that my VIN is in the affected range. I have not ever had the P0401 codes, or any of the engine shaking reported by others. My goal was strictly preventative maintenance, i'm hoping to keep this car a lot more miles!

    On disassembly i found the EGR pipe was pretty clean, only a thin layer and some chunks of carbonized oil. The inlet from the EGR valve (to the EGR pipe) had a similar crispy thin layer, but not obstructed. I didn't touch the EGR valve itself, or cooler, just the EGR pipe forward. The intake manifold did have maybe 1-2 TBSP of oil below the throttle body. The throttle body had a fair amount of carbon on it. The intake manifold itself, and the intake ports in the head, were similar to above and had a thin carbon layer, but no clogs. I inspected and blasted the EGR ports in the intake manifold for each cylinder, and confirmed that all were free and clear enough to circulate gas.

    So basically, on my 160k 11 year old Gen 3, which i don't believe has had any prior EGR service, it was totally fine. That said, your mileage may vary of course, along with driving style, trip duration, etc. I'm glad i found no issues. I only wish i had bought two cans of manfold cleaner, instead of one! I did not get too crazy about getting the intake manifold spotless, but did give it some blasts of cleaner, a bit of scraping and wiping, new gaskets, and put it all back together.

    Will i do this every 50k miles? maybe... maybe not. I will probably do it at least one more time, and see if it continues to NOT be a problem for me.

    FWIW, i'm religious about oil changes every 5k miles, and use full synthetic. I have no oil consumption at all.
     
    #19 Nick Seifert, Nov 2, 2023
    Last edited: Nov 2, 2023
  20. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,323
    15,110
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV