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How to prevent the 3rd Gen Prius Headgaskets failure!

Discussion in 'Gen 3 Prius Main Forum' started by Kaptainkid1, May 14, 2022.

  1. burebista

    burebista Active Member

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    You are right. :)
    At least I didn't see a groundbreaking difference before/after cleaning IM and EGR pipe.
     
  2. Lares_Mat

    Lares_Mat Member

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    :):) I never heard this :D

    But - it is not a bad Idea to clear leaves from a gutter at any day, I think (if I understood it right - English is not my first language).

    My question was aimed to better understand, what would happen, if I would clean the IM, and not the cooler.
    You are probably right - it will have an impact on the flow, but I think, if your ports are clogged that much, that cleaning them could make an impact, your cooler is clogged heavily too, so not cleaning the cooler in this case would result in, maybe, only a slight change in the overall flow (and more even flow between the cylinders).

    I am starting with my 19,94 kPa, which is not bad - not heavily clogged, I suppose.
    In this case cleaning the IM is an easy work, which would even out the relative EGR flow between the cylinders.
    And I could save the cooler cleaning to the point at which I decide to get new spark plugs to the motor, and I have to dismantle a half of my car anyway ;)

    Mat
     
  3. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah if you've cleaned the intake you've at least evened out what flow there is.

    Taking off the wipers and cowl is not that difficult. Have you watched the @NutzAboutBolts (spark plug) video? They're all linked here:

    Nutz About Bolts Prius Maintenance Videos | PriusChat

    It takes about 30 minutes, taking it off or putting back. Do drain a couple of quarts of coolant from the radiator before taking out the cooler; it'll drop the coolant level lower than the EGR components, avoid any coolant spillage.
     
  4. Lares_Mat

    Lares_Mat Member

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    Yes, I saw the videos - very interesting!

    I'm trying to optimise the work. It seems, that at this time I do not have to clean the cooler - the flow seems to be OK, but the difference between cylinders might not be, so it is more urgent, not mentioning of getting rid of all the oil in the IM ;)

    Mat
     
  5. ASRDogman

    ASRDogman Senior Member

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    It is BEST to clean everything in the egr circuit at the same time.
    Cooler is most important, intake passages are second. The are what clogged.
    If the egr pipe is clogged, the engine wouldn't run. But the cooler clogs way before that.
     
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah looking back through your previous contributions, you're around 90K kms, aka around 60K miles. Which "is" early. And you can delay some. I am very OCD, did ours around 70K kms. Don't regret it, carbon was building up, and I will likely do again before long, maybe this fall when our spark plugs are due (12 years).

    One thing, the second time you do it will be much easier/faster.

    If you want to slow down it's return, consider an Oil Catch Can.
     
  7. StarCaller

    StarCaller Senior Member

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    or two / ;)
     
  8. ChapmanF

    ChapmanF Senior Member

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    The ports are responsible for the evenness of flow, but of course they only affect that in one direction. It's not as if some of them become more clogged and others become more open.

    So they have both a "common mode" effect (reducing overall flow), and a differential mode effect. The common mode part is detectable on the monitor test, same as clogging anywhere upstream. The differential part isn't.

    The EGR valve has a wide range of motion, so to some extent the ECM can compensate for whatever common-mode obstruction it detects (no matter where in the system) by opening the valve a bit more. In the presence of differential IM clogging, that likely means the more-clogged cylinders are getting too little and the less-clogged ones are getting too much, and the average comes out around what the ECM wants.

    The cylinders getting too much are luckier; they may misfire, and contribute that way to rough running, but they aren't at detonation risk like the ones getting too little.
     
  9. Lares_Mat

    Lares_Mat Member

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    Now my thoughts are going wild ;)

    One or two oil catch cans... Yes, I saw the oil down in the IM - it should NOT land there.

    If I look at the PCV valve, it sits at some "plate", which seems to cover something like an oil separator, which is apparently not enough...

    Could we not help the existing oil separator work better somehow?

    Mat
     
  10. Lares_Mat

    Lares_Mat Member

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    I absolutely agree!
    So cleaning the IM ports (in my case - not heavily clogged) would have priority over cleaning the cooler, which could wait for better occasion ;)

    Mat
     
  11. ChapmanF

    ChapmanF Senior Member

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    My opinion is just one among many, but yes, that's also the way I see it.
     
  12. CR94

    CR94 Senior Member

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    Yes. That's why I cleaned out my manifold last year, even though I'm not in a great position to attack the cooler. None of the ports appeared to be badly clogged, although I could see some black gunk. I found oil in the manifold, which is semi-normal.
     
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  13. ToyXW

    ToyXW Active Member

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    You should change Toyota Super Long Life coolant every 5 years, regardless of mileage. Toyota has at times specified 5 years 100,000 and 5 years 150,000 mile intervals (on other cars), but that's far outside any Toyota warranty so Toyota only really cares if it affects their reputation.

    As coolant ages, its corrosion inhibitors break down. When this happens, the coolant can start to break down the coating on the metal head gasket, especially the early gen 3's which had a different head gasket.

    I do think EGR play a part. I suspect the cylinders with clogged EGR ports run a bit hotter and experience more (mild) detonation. Detonation can cause the head to lift, which can introduce acidic combustion byproducts into the coolant and allow the increasing acidic coolant to travel farther and farther past the sealing ring.
     
    #73 ToyXW, May 21, 2022
    Last edited: May 21, 2022
    Kaptainkid1 and bisco like this.
  14. fil100

    fil100 Junior Member

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    Tried really hard to replace the egr cooler on my 2010 prius yesterday. Have a new one ready.

    The only problem is the lower screw. I simply could not access it. I can feel it but there are so many hoses and cables.
    Will try again next week with some more tools....

    Do you have tips for removing it?
     
  15. Mendel Leisk

    Mendel Leisk Senior Member

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    I had success with a relatively short combo, maybe a long socket (12 mm?) on 1.5" extension, on a 1/2" to 3/8" adapter, on a long handled 1/2" jet wrench with swivel head. The swivel head helps. Also, might help to remove the hold-down bolts of the brackets of cables in the vicinity; pull everything out of the way as much as possible.There's a largish coolant hose (with braided mesh sheathing?) right beside the target nut. As you're facing from driver's side the nut is around 3 o'clock relative to that coolant hose, very close by.

    Strategy: you can get that nut off, any time, without needing to remove any other components. Best done first, when you're fresh, and leave the dang thing off.

    For extra points, back out the stud too. That took me a solid half hour, with a tiny 1/4" drive Jet wrench and Torx socket. Very difficult to turn at first, was scared I'd round off the head. Left that dang thing off too. There was so little room to turn the wrench it was like one click at a time.
     
  16. ChapmanF

    ChapmanF Senior Member

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    I saved the solid half hour, and any worries about rounding the stud, and just left the stud in place.

    Once the two studs at the rear of the cooler are removed (which didn't give me any trouble), there's no need for the evil one underneath to be removed. The cooler slips right off it. For installation, it also slips right back on and hangs there peacefully for you while you get it recombobulated at the ends.
     
  17. burebista

    burebista Active Member

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    OK, in this weekend I've played with OBDLink app. Compared with dashboard, Torque and Hybrid Assistant.
    My conclusion is that Hybrid battery pack remaining life is in fact SoC so nothing to worry about. :)

    If you want an approximate test of hybrid battery you could try Dr. Prius app.
     
  18. Lares_Mat

    Lares_Mat Member

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    Have you seen the Hybrid battery pack remaining life changing with the SoC?

    It would be an absolutely stupid naming for SoC ;)

    Mat

    PS. You can do a good hybrid battery check with HybridAssistant, but , I think it will not give you any percentage of remaining life of the pack - you have to judge it yourself based on the delivered data.
     
  19. burebista

    burebista Active Member

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    Yes, same percent in Torque and Hybrid Assistant.

    And yes, pretty awkward choice for naming. o_O

    Dr. Prius gives you a "guesstimate" remaining life. Better than nothing but I have confidence in jacktheripper. He's behind Nexcell LiFePO4 battery pack.
     
  20. AnneN

    AnneN Junior Member

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    Hi. Can you tell me how you get the readings on the Non Continuous Monitors please? When I select that option I get a screen with a bar at the bottom that says Reading. The reading takes 2-3 minutes then just a blank screen - how do I get it to show me the results of the readings as you have above?
    Thanks