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Gen4 to Gen3 engine swap using gen 4 intake and egr, DONE!

Discussion in 'Gen 3 Prius Technical Discussion' started by Dave Hanson, Aug 13, 2019.

  1. OGyanggang2020

    OGyanggang2020 Junior Member

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    I found out the rings are worn out causing oil consumption. I believe that, along with a poorly maintained EGR contributed to the issue.
    It hasn’t like failed catastrophically. I just had the terrible knocking from a cylinder 1 misfire yesterday morning and assume the worst. I’ve been working too much to trouble shoot but assuming the worst for now.
     
  2. SFO

    SFO Senior Member

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    Was the electric water pump ever replaced?
    What brand and weight of oil was used, and what was change interval ?
     
  3. Mendel Leisk

    Mendel Leisk Senior Member

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    Just musing: an EGR design that clogs royally (which raises combustion chamber temps, starting with cylinder 1) a water pump that slowly goes downhill (and also raises temps), and no coolant temp gauge; what a perfect storm.
     
  4. tvpierce

    tvpierce Senior Member

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    I learned in another thread that the heads are plumbed differently between the Gen 3 & 4. So in order to get a Gen 4 engine to work, you'll either need to do some modifying, or re-use your Gen 3 head... in which case you're doing another head gasket job. You would be gaining the updated pistons/rings of the Gen 4, and presumably a lower mileage engine though.

    (EDIT: Disregard this last part. I didn't see your response further down.)
    But I have the same question as @ASRDogman, what caused the second head gasket failure at only 30K miles? That should have lasted 200K+.
     
  5. mjoo

    mjoo Senior Member

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    He's assuming it's a head gasket without diagnosing. Assuming makes an a$$ out of u and me.
     
    #65 mjoo, Dec 10, 2020
    Last edited: Dec 10, 2020
  6. ASRDogman

    ASRDogman Senior Member

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    How did you find out the rings are worn out?
    Did you do a compression test? Did you pull the head and look at the cylinder walls?
    Did you pull the pistons and find the rings sticking or broken?

    A poorly maintained EGR circuit could cause the head gasket to fail.
    Is the coolant low? Have you had to add any?

    Never ASSume..... Test and verify.... Seems you are just guessing by things you've read.

     
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  7. Mendel Leisk

    Mendel Leisk Senior Member

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    Procure a new gen 4 short block, and rebuild your head? Though IIRC, 4th Gen short blocks are pricier than 3rd.

    It's likely a new gen 3 block has revised pistons/rings, but even if not: it'll likely outlast the car. Especially if you fall back to a 5k oil change, ignore Toyota's "recomendation".
     
    #67 Mendel Leisk, Dec 10, 2020
    Last edited: Dec 10, 2020
  8. cnc97

    cnc97 Senior Member

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    There are several short blocks on eBay right now. 1300 to 1900, depending on whether it’s Gen 3 or 4.
     
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  9. Mendel Leisk

    Mendel Leisk Senior Member

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    You essentially did a 4th Gen short block swap, from 4th Gen salvage engine. Still have the head? Just curious.
     
  10. cnc97

    cnc97 Senior Member

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    I sent that to scrap during the spring.
     
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  11. tvpierce

    tvpierce Senior Member

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    The last time I looked at complete engines from salvage yards, the Gen 3 was more expensive than Gen 4. I presume because there's not much call for replacing a Gen 4 engine, while Gen 3 are getting to the age/mileage that the head gasket failures and oil burning are driving up demand for replacements.
     
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  12. Mendel Leisk

    Mendel Leisk Senior Member

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    I checked recently on Amayama: price for a 2015 and 2016 model year short block were "equally onerous", lol. They were different part numbers (assembly number?), but oddly were identical in price. It was a bit of a gut-punch: $2900+ CDN for the block, and around $700 for shipping. It's only money... :cry:

    With our low miles and insanely frequent oil changes (every 6 months, hang the low kms), and considering it's yet to consume a drop by nearly 90K kms, it's probably cargo-cult for me. But it's interesting.
     
  13. Prodigyplace

    Prodigyplace Senior Member

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    I thought you were looking to cash in and sell your gem of an engine. :ROFLMAO::ROFLMAO:
     
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  14. johnnychimpo

    johnnychimpo Active Member

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    This strictly for the V right if you use all the gen three parts no mods needed correct?
     
    #74 johnnychimpo, Mar 2, 2021
    Last edited: Mar 2, 2021
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  15. Mendel Leisk

    Mendel Leisk Senior Member

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    I
    I believe the process is identical for reg gen 3 and the v. And yeah if you’re swapping in a gen 3 engine no coolant mods needed, for either model.
     
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  16. johnnychimpo

    johnnychimpo Active Member

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    Can you point me in the right direction, I'm looking to do the gen4 engine to gen 3 keeping all gen three parts non v prius.
     
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  17. johnnychimpo

    johnnychimpo Active Member

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    To be clear I'm installing gen 4 engine in gen 3 prius.
     
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  18. Mendel Leisk

    Mendel Leisk Senior Member

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    Then those videos are the way to go. The process is the same, Prius or Prius v. @Ragingfit first did a reg 3rd gen Prius thus.
     
  19. johnnychimpo

    johnnychimpo Active Member

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    So I understand you cant use the Gen 4 EGR but you can use the gen 4 intake right? if so what do I need to mod to get it to work? can you point me in the right direction?
     
  20. Mendel Leisk

    Mendel Leisk Senior Member

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    Really not sure. Play it safe and use gen 3 intake??