Easier to swap in a used engine or do a head gasket replacement?

Discussion in 'Gen 3 Prius Technical Discussion' started by weapon, Jul 9, 2026 at 9:37 AM.

  1. weapon

    weapon Junior Member

    Joined:
    Jan 20, 2020
    45
    12
    0
    Location:
    OR
    Vehicle:
    2010 Prius
    Model:
    III
    Looks so simple to swap in a used engine vs the head gasket.

    Am I correct?

    What are some of the pitfalls of a swap?
     
    #1 weapon, Jul 9, 2026 at 9:37 AM
  2. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,933
    8,643
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    a pitfall would be the used engine you put in will have more problems than the one you're replacing. But since you have a 2010, considered the worst engine year for 3rd generation, it probably would benefit you more than the potential pitfall to swap engine
     
    #2 JC91006, Jul 9, 2026 at 10:44 AM
    Last edited: Jul 9, 2026 at 12:24 PM
    Mendel Leisk and weapon like this.
  3. weapon

    weapon Junior Member

    Joined:
    Jan 20, 2020
    45
    12
    0
    Location:
    OR
    Vehicle:
    2010 Prius
    Model:
    III
    Yes that is a major concern I do have right off the bat. I have been watching the head gasket replacement videos and it seems really labor intensive and lots of places for user errors if not careful.

    When I did the manifold/egr swap, I was looking at the engine and it seemed like a relatively simple engine swap. It just seems to be a very well enclosed process. I would for sure try to get a low milage 2015 replacement.
     
    #3 weapon, Jul 9, 2026 at 10:51 AM
  4. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    8,034
    4,073
    0
    Location:
    Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    How many miles do you have on the engine? Is it burning oil?
    Replacing the head gasket is less expensive. As long as the head is not warped.
    Did the engine overheat? If you are replacing it because it JUST started leaking, you're likely okay.

    Replacing the engine is not really a "hard" job, just a lot of steps. If you go slow and take your time,
    you'll be able to do it if you have the ability.

    But putting a used engine in, is risky. Do you KNOW it's from a 2015? Do you KNOW if the mileage is
    actually the REAL miles. How well do you trust the people you'll getting the engine from?

    It would be best to get a remanufactured engine.

     
    #4 ASRDogman, Jul 9, 2026 at 11:48 AM
  5. weapon

    weapon Junior Member

    Joined:
    Jan 20, 2020
    45
    12
    0
    Location:
    OR
    Vehicle:
    2010 Prius
    Model:
    III
    It is the one with the pink goop issue from my other post. Almost 200k. Been burning oil for the last 5 years. 1& 3 spark plugs were coated in oil when removed during the cleaning. Got it all back together and the pink goop has returned. I also noticed that the torque power is lower on this one vs my 2010 with only 160. Every day I drive it, she just keeps hinting to me it has head gasket issue. Not fully blown but small leak.

    After more research, with the oil burn and the head gasket, I might be better to just find a 2015 engine and do a swap instead of putting a bandaid over the probably ring issue.
     
    #5 weapon, Jul 9, 2026 at 12:30 PM
  6. Mendel Leisk

    Mendel Leisk MMX GEN III

    Joined:
    Oct 17, 2010
    61,401
    42,250
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Maybe ask @Tideland Prius to merge threads?
     
    #6 Mendel Leisk, Jul 9, 2026 at 12:33 PM
(You must log in or sign up to post here.)