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

Gen4 engine fit gen3?

Discussion in 'Gen 3 Prius Main Forum' started by Jose Reyes, Dec 18, 2018.

  1. Jose Reyes

    Jose Reyes Junior Member

    Joined:
    Dec 10, 2016
    63
    21
    0
    Location:
    Anaheim
    Vehicle:
    2010 Prius
    Model:
    V
    Im curious if anyone has looked if the gen 4 engine will fit the gen 3. The gen 3 has a tendency to burn oil and blow head gaskets.
     
  2. Raytheeagle

    Raytheeagle Senior Member

    Joined:
    Jul 1, 2016
    11,257
    15,491
    0
    Location:
    Bay Area, California
    Vehicle:
    2019 Prius Prime
    Model:
    Prime Plus
    @cnc97 has done the swap.

    It is possible with some Frankensteining of parts(y).
     
  3. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    11,518
    14,128
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius
    Model:
    Two
  4. Jose Reyes

    Jose Reyes Junior Member

    Joined:
    Dec 10, 2016
    63
    21
    0
    Location:
    Anaheim
    Vehicle:
    2010 Prius
    Model:
    V
    Seems like it. But, I definitely think it's worth it vs rebuilding a gen 3 engine. Based from what i read the biggest issue the cooling situation and having to use the gen4 intake and airbox. I'm guessing that you also have to transfer the electronics.
     
  5. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    11,518
    14,128
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius
    Model:
    Two
    I don't know for sure, but @cnc97 would know. Hopefully he can give you some insight when he sees this.
     
  6. Mendel Leisk

    Mendel Leisk EGR Fanatic

    Joined:
    Oct 17, 2010
    56,671
    39,221
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Oh have I got a movie for you:

    Swapping in a Gen 4 Prius' 2ZR Engine into the Prius v | PriusChat

    Caveat: the vehicle getting the transplant is a Prius v, but it's equally applicable to any 3rd gen. This was @Ragingfit 's second transplant, and the first was to a regular 3rd gen Prius.

    He retains third gen intake (with throttle body) and exhaust, and EGR system. The latter basically free-spans from the intake manifold to exhaust, without connection. A nub on the side of the donor engine needs to be cut back.

    There's some modification to the engine coolant plumbing, addition of a short piece of pipe.

    Another option: transplant a 2015 engine, they are the one 3rd gen year with both revised pistons and oil rings, both with the aim of reducing oil consumption problems.

    Basic questions:

    1. What miles on yours?

    2. How's the oil consumption?
     
    #6 Mendel Leisk, Dec 18, 2018
    Last edited: Dec 18, 2018
  7. Prodigyplace

    Prodigyplace 2025 Camry XLE FWD

    Joined:
    Nov 1, 2016
    11,799
    11,362
    0
    Location:
    Central Virginia
    Vehicle:
    Other Hybrid
    Model:
    XLE
    If he keeps the 3rd Gen EGR, won't it develop the 3rd Gen issues? I thought the EGR change was what we thought fixed the Gen 4.
     
  8. Mendel Leisk

    Mendel Leisk EGR Fanatic

    Joined:
    Oct 17, 2010
    56,671
    39,221
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    It's difficult to bring the fourth gen EGR over, would require the fourth gen exhaust system to come over as well, or a lot of cutting and welding. @Ragingfit muses a bit on the subject, shows 3rd and 4th gen exhaust mainifolds, how they differ (at the beginning of video #8).

    There might be fit issues at the intake manifold end as well, not sure. Third gen EGR is not a total disaster: periodic clean-out, say every 80~100K miles, and it's fine.

    There's many reasons for swapping in a 4th gen salvage engine. Definitely foremost: they're cheap, low mileage and plentiful. Also, it's likely Toyota's likely learned some lessons regarding oil consumption, with the piston and rings with 2010~2014 3rd gen, and carried that over to 4th gen.
     
    #8 Mendel Leisk, Dec 18, 2018
    Last edited: Dec 18, 2018
    Ragingfit and Bay Stater like this.
  9. zinzet

    zinzet Junior Member

    Joined:
    Jul 27, 2022
    15
    4
    0
    Location:
    Federal Way
    Vehicle:
    2012 Prius
    Model:
    Base
    Hi. Does anyone know will Prius prime 2021 engine fit prius gen 3?
     
  10. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    110,132
    50,048
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    if it's the same engine as the regular prius, it should, but i would wait for more experienced knowledge
     
  11. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    11,518
    14,128
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius
    Model:
    Two
    It is the same engine as the regular Gen 4 with the exception of the sprague clutch that allows the Prime to get up to 84 mph in EV. That would have to be changed out for the regular damper clutch.
     
    bisco and zinzet like this.
  12. Mendel Leisk

    Mendel Leisk EGR Fanatic

    Joined:
    Oct 17, 2010
    56,671
    39,221
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    I'm fuzzy, but does the damper need swapping anyway, you need to transfer over (or get another, if it's damaged) a gen 3 damper? @Ragingfit ?
     
    jerrymildred likes this.
  13. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    11,518
    14,128
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius
    Model:
    Two
    Good question. I think I read about it, too, but can't remember any details.
     
    Mendel Leisk likes this.
  14. Mendel Leisk

    Mendel Leisk EGR Fanatic

    Joined:
    Oct 17, 2010
    56,671
    39,221
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    In one of the last videos on the series @Ragingfit goes into detail about the damper.
     
    jerrymildred likes this.
  15. Ragingfit

    Ragingfit Active Member

    Joined:
    Oct 21, 2015
    189
    246
    0
    Location:
    Aurora, IL
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    You must put the damper that goes with the car on the engine.
     
    Mendel Leisk likes this.
  16. HelloMcFly

    HelloMcFly Member

    Joined:
    Aug 21, 2022
    34
    41
    0
    Location:
    Oklahoma City
    Vehicle:
    2011 Prius
    Model:
    Five
    I just performed this swap. It was a lot more modifying then I originally thought. Not recommended for the DIY’r
     
  17. techguy802

    techguy802 Junior Member

    Joined:
    Mar 16, 2018
    20
    18
    3
    Location:
    VT
    Vehicle:
    2012 Prius
    Model:
    Two
    I did it on mine. I kept the 3rd gen intake, airbox, egr, oil dipstick tube etc. Basically followed Ragingfit's guide. The worst part was modifying the metal lower radiator hose pipe to be shorter. There were also some rigid metal coolant pipes that came still attached to the gen 4 engine that completely threw me off on the coolant hose routing before I removed them.
     
  18. zinzet

    zinzet Junior Member

    Joined:
    Jul 27, 2022
    15
    4
    0
    Location:
    Federal Way
    Vehicle:
    2012 Prius
    Model:
    Base
    Hi. Finally installed 2021 prius prime gas engine into 2013 prius. Already made 3000 miles (including 2 trips 750 miles/day each) and the car runs perfect.
    Things were kept:
    1. Intake
    2. Exhaust manifold (had to bent egr cooler pipe)
    3. Some coolant hoses
    4. Damper
    New parts from prius prime 2021:
    1. Engine
    2. Egr valve
    3. Egr cooler
    4. Some coolant hoses
    Custom parts:
    1. Coolant tee
    2. Handmade metal gasket between intake and egr valve, to lower down the output hole of the gen 4 egr valve pipe.
     
    Mendel Leisk likes this.
  19. Mendel Leisk

    Mendel Leisk EGR Fanatic

    Joined:
    Oct 17, 2010
    56,671
    39,221
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Interesting: post gasket hole ID? And update how it goes. Thanks.