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JDM Engines the same as US Spec?

Discussion in 'Gen 3 Prius Technical Discussion' started by ZBrink, Mar 3, 2021.

  1. ZBrink

    ZBrink Member

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    My 2010 Prius has burned oil since just after 100k and my head gasket may be going out. I'd like to swap the motor but don't want to "upgrade" to a Gen4 motor.

    I want a 2015 engine as Toyota had resolved the issue of the piston rings for that year. My local JDM told me they have no way to identify which model year the engines came from (that blew my mind) but that it didn't matter because the JDM engines didn't have piston ring problems like our cars. My engine was built in Japan just like the JDM ones. I'm skeptical and didn't believe the guy. He couldn't show me any documentation to back up his claim.

    Can anyone verify or discredit this?
     
  2. Hairy Cannonball

    Hairy Cannonball New Member

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    Just take your original engine apart, and rebuild it using the latest spec Toyota parts. Why mentally masturbate over JDM this and JDM that?
     
  3. ASRDogman

    ASRDogman Senior Member

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    You CAN use a Gen4 engine. Just use the head from the Gen3 engine.
    If you keep the Gen4 head, you'll have to do some bending and modifying of the exhaust for the egr cooler.
    Not sure about then not knowing what year the engine came from. They should, buttttt....
     
  4. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    I find it sorta hard to believe that the bottom end of a JDM XW30 engine would be different than a North American spec motor, but I cannot credibly discredit what the salesperson told you.

    TL ; DR
    They probably do not have the piston ring problems, but they probably have the same piston rings.
    I would buy one unreservedly...AFTER a FULL visual inspection and WITH a verifiable warranty.

    Longer version:

    There are some interesting urban legends (myths) that surround JDM engines, and most of them are hooey.
    They mainly result from cultural differences AND a system of inspections in the Japan called Shaken.
    Motor-vehicle inspection (Japan) - Wikipedia

    The "official" purpose of Shaken inspections is public safety....sorta like CARB in California.
    The REAL purpose of this system of inspections is to encourage people to drive newer cars (because Japan's economy used to be based ON.......???) and to create government jobs and levy taxes disguised as "fees".....just like CARB in California.
    Author/Historian Dan Carlin said in his podcast about Japan that “The Japanese are just like everyone else, only more so.” which sums it up fairly nicely.

    So.....
    Here's why JDM engines are "probably" > US-spec engines:

    1. They're more anal about maintenance than lazy Americans.
    2. If you've ever been to Japan then you know that driving is expensive, and built to STAY that way. Gas is expensive. Tolls are more widespread. Taxes are Insane.
    3. Many Many Many more people in JA use public transit when and where they can for regular hops reserving their cars for irregular trips.


    HERE is where they may NOT be > than US-spec engines:
    1. The myth that JDM engines have never been flogged and dogged is just that....a.myth.
    Ever been to California?
    Yeah.
    Me too.
    Ever see a bunch of cars that made you wonder HOW the Eff they EVER passed CARB inspections when you can't even legally use an Oil Catch Can?
    The reason is simple.....they either DIDN'T and don't give a crap....found a mod-friendly shop to gundeck the inspection....OR....they "made their car legal" just long enough to pass a REAL inspection.
    Japan has tuners just like everybody else....only MORE so. ;)

    2. The myth that JDM engines are limited to xxxxx miles is balloon juice. They have high mileage cars....just like everybody else. Japan is just about the size of California. Bigger if you flatten it out. Some cars pull intercity duty. Some get used as taxis. Japan has Uber.

    3. Ever driven in Japan? I have....and it's kinda exiting, and NOT just because they drive on the wrong side of the road!
    Here's the thing....they actually have FEWER accidents than US drivers despite their rather interesting driving style. This due to very obvious factors...BUT.....they DO have them.....juuuust like everybody else.
    Shaken regs make it harder to produce 'zipper' cars like we have in the US, and one of their capital crimes is probably title washing and odometer fraud...and yes....like most developed nations they they DO have the death penalty!
    Fun Fact:
    In JA you only get executed one way.
    Hanging. :eek:
    So....this means that your low mileage JDM motor "may" have a much better chance of originating from a "previously un-wrecked" car.

    4. Traffic Patterns. Which engine would you rather buy? One that has been driven in ultra-dense city traffic or more of a highway warrior?
    Remember.....a JDM engine MIGHT only have 40,000 miles on it but how many hours did it spend idling in log-jammed traffic with the owner whamming away furiously at the steering wheel? It MIGHT be like buying a police car here in the US (only without the damage from "peaceful" demonstrations.)

    5. Efficiency.
    Engines are heavy, and they have a life cycle of well over 100,000 miles.....even when they are owned by people whose idea of 'proper maintenance' is tossing the keyfob on a service manager's desk every 10,000 miles and asking how much it will be THIS time.

    Why ship them HERE? ;)

    YMMV
     
    #4 ETC(SS), Mar 4, 2021
    Last edited: Mar 4, 2021
    Coots likes this.
  5. ChapmanF

    ChapmanF Senior Member

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    I hate trick questions.
     
  6. sam spade 2

    sam spade 2 Senior Member

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    Wait.......what......you have a car that needs BOTH a new hybrid battery AND a new/rebuilt engine ???
    And you are seriously considering going that ???
    Something is wrong with this picture. :eek:
     
  7. ZBrink

    ZBrink Member

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    What's wrong with this picture? 2010 is the worst model year for the Gen3 and mine was built in 2009 so it's more than 11 years old. None of my problems should be a surprise. The battery still functions but it's on the decline. The engine still runs too but burns a quart maybe every 1500 miles which is terrible for a Toyota engine with this few of miles. The head gasket "may" be going too. A JDM is $1200 and a Toaster kit is $1600. Not bad for a total refresh on an otherwise car in good shape.
     
    ASRDogman likes this.
  8. cnc97

    cnc97 Senior Member

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    When you can get the Gen 4 engine for $700-800, why not save the few dollars and get the better engine? The JDM engine will at some point do exactly what the current engine is doing now. July 2018 I put the Gen 4 short block in mine. The local yard to me that listed a “running core” 2010 1.8 with 200k for $1400 still has that engine now. At the very least, be particular about the replacement engine, and get the newest, lowest mile engine that you can get.
     
  9. sam spade 2

    sam spade 2 Senior Member

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    And when you are done you will STILL have a car that is over 11 years old, with other parts likely to fail right along.
    Not to mention the time and trouble you will have invested.
    Not a wise decision in my book.......but to each his own.
    Good Luck !!
     
  10. analoggirl

    analoggirl Member

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    so you can put the GEN four engine in the GEN three? Getting whiplash trying to figure out if this is possible.
     
  11. ASRDogman

    ASRDogman Senior Member

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    It can, and has been done, but they seem to always have engine cooling issues.
    If you can a remanufactured gen3 engine, you will be fine. If it's installed correctly.

     
    #11 ASRDogman, Sep 5, 2024
    Last edited: Sep 5, 2024
  12. analoggirl

    analoggirl Member

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  13. analoggirl

    analoggirl Member

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    wondering if you can help...
    The mechanic, that I don't trust and not going back too, tells me he can get me a 2013 JDM engine with 35,000 miles.
    From everything I've read in this group, or researched online, this isn't possible.

    this is the article he sent me. What's the truth here?

    How To Buy a Used Auto Parts Online | Kaiho Industry
     
  14. ASRDogman

    ASRDogman Senior Member

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    NO ONE knows exactally how many miles are actually on a jdm engine.
    Except for the company that pulled the engine.......

    "MY" personal opinion is to have the headgasket replaced.
    Locate a shop that works on hybrid cars, and specifically the Prius.
    Have them do it. Have them check for leaking valves.
    Certainly someone here can point you in the right direction in NC.
    I've seen recommendation in the past but call recall them.

    Or purchase a remanufactured engine from the hybrid pit in california.
    They would seem to be the most reliable.

    You haven't stated how much oil your car burns. Or what your budget is.
    The head gasket would be the least expensive route.
    A JDM engine averages around $1500. Reman from the hybrid pit is about $2000,
    depending on which version you get.
    Since I would guess you would want something that is done correctly the first time,
    and you can feel safe driving the car for the 200,000 miles, you want the most
    reliable thing you can afford.

    Let's say $2500 for the H.P. reman engine with new water pump and thermostat.
    I would "guess" $1500 to install it. So $4000, less tax... So if you say $5000, you have
    a decent estimate. You could possibly get a personal loan for $5000. Pay as much as
    you can every week to pay it down quicker. Minus any "cash" you have now so you can
    get a loan for less money.

    That's a lot less than a new car at $35,000 or more. And less insurance cost

    Obviously if you had the skills to do the labor yourself, or a "friend" that would help, it
    would be a lot less. But not everyone can do that or has a friend that can.

     
  15. ASRDogman

    ASRDogman Senior Member

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    #15 ASRDogman, Sep 5, 2024
    Last edited: Sep 5, 2024
  16. ASRDogman

    ASRDogman Senior Member

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    Also, the 2013 engine (and HOW would he know that?) has the older style pistons/rings.
    So you'll likely get oil burning. You would want the 2015 engine. Which NO ONE knows for
    the JDM engine since there is no vin or engine number. It's just a guess.
     
    analoggirl likes this.
  17. analoggirl

    analoggirl Member

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    The car burns no oil. The shake rattle and roll has been happening intermittently for 2 1/2 years. The mechanic, that I won't go back to no longer trust, repaired my coolant reservoir three times. And then sent me on my way on a 14 Hour road trip. The car overheated and when I came back, he said it was still leaking. he said it was fixed and I went back on that road trip to get my daughter and the water pump blue in the middle of the night in the middle of nowhere. So knowing that this leak has probably been going on for 2 1/2 years as he tells me, it's something else, I don't want to take the chance of replacing the head gasket only to find out More damage has been done. I don't know where you are, but those prices are nowhere near what they are here. Most mechanics are quoting 4000 in labor alone for the head gasket. Let's say 6000 total. Replacing the engine is cheaper. There's a local mechanic that I trust who doesn't have a lot of experience in pries. He says he feels comfortable swapping out the engine. He'd like me to do all the footwork, since that's not his thing.
    to me. It looks like you can only buy it in bulk. I sent them a message. See if they reply
     
  18. ASRDogman

    ASRDogman Senior Member

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    Okay, then contact the Hybrid Pit, and order a remanufactured engine from them.
    With a new waterpump and thermostat, already installed.

    Those prices were "guesses" from what people have quoted on Prius chat.
    Since I do all my own work, I have no idea what the labor rate is any longer.