How common is Gen 2 Head Gasket Failure after 300,000 miles?

Discussion in 'Gen 2 Prius Main Forum' started by PrimalPrius, Feb 6, 2026.

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  1. PrimalPrius

    PrimalPrius Junior Member

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    Cliff's notes:
    Even after head gasket replacement, coolant is still mixing into oil (but not into cylinders as far as I can tell and not oil into coolant). Coolant does not even have to be under pressure, but engine has to be running.
    Failure is either head gasket or a block crack or head crack that opens only when engine is running.
    Guesses?
     
    #41 PrimalPrius, Apr 22, 2026 at 1:38 PM
    Last edited: Apr 22, 2026 at 1:46 PM
  2. Tombukt2

    Tombukt2 Senior Member

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    I've got too many engines sitting around here that are good to worry. I might tear it down later and see what I see but probably not much to see .
     
    #42 Tombukt2, Apr 22, 2026 at 2:15 PM
  3. PrimalPrius

    PrimalPrius Junior Member

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    I don't understand.
     
    #43 PrimalPrius, Apr 22, 2026 at 2:26 PM
  4. Tombukt2

    Tombukt2 Senior Member

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    I have a bunch of engines cars and parts here on my property so before I go crazy with diagnostics . I can swap the engine about as quick as hair pulling . Then later should I decide I can tear the stuff up that I took out of the car and I can play surgeon or such . I mite never find the problem . But I'll be driving the car 24 hours later for another 10 or so years . That's kind of what I mean..when I'm all in . I am..
     
    #44 Tombukt2, Apr 22, 2026 at 4:10 PM
  5. PrimalPrius

    PrimalPrius Junior Member

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    Yeah, sounds like a plan. I'm thinking about picking up a used engine, but that could, of course, come with its own set of problems.
     
    #45 PrimalPrius, Apr 22, 2026 at 4:17 PM
  6. Tombukt2

    Tombukt2 Senior Member

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    Well the ones I have here are in cars that I was driving that daughters and so on have plowed into other cars so they were running perfectly when they got smashed . Do I'm just removing my running perfect engine out of my kid wrecked chassis . Why i save them . So 8 know the three here are fine . They been mine for oh 10 plus years. No smoking no lights on etc
     
    #46 Tombukt2, Apr 22, 2026 at 6:13 PM
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