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Head Gasket Failure

Discussion in 'Gen 3 Prius Technical Discussion' started by donzoh1, Dec 28, 2023.

  1. donzoh1

    donzoh1 Active Member

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    25K miles ago, the P0300, 01, and 02 codes indicated EGR clogging which was thoroughly cleaned, along with intake manifold cleaning and input damper plate was replaced. Everything was going well, until I hit a block of ice causing gradual oil starvation. I got my passengers to the airport (probably ten miles). Although the oil light was on for about 5 of the 10 miles, the light went off briefly when parking, showing there was at least something left on shutdown. Adding new oil and liquid head gasket fix, the car ran great and mileage went from the 42 mpg of the past 25K miles to 48 mpg for the last 500 miles.

    I thought of myself as a genius...for awhile. Then the coolant started disappearing with at least one episode reaching 240 degrees coolant temp. Also, there was excessive crankcase pressure, although I'm thinking this may have been going on previously. Whether the liquid gasket repair failed because I didn't follow instructions I have no idea. I've read that some people have had long term success with such products but the Gen 3 Prius seems to have a real vulnerability between Cylinder 1 and Cylinder 2 with combustion gasses bypassing into coolant or into the adjacent cylinder.

    Anyway, the engine block and head seem flat and there is still some cross hatching visible so I'm putting things back together with new gasket and bolts. I know a new motor or even JDM is probably a better long term play but don't want to part with $2K or $6K or whatever the current numbers are.
     
  2. donzoh1

    donzoh1 Active Member

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    The head gasket is bowed about half an inch although the block deck and cylinder head are flat. There's a clear defect between Cylinder 1 and Cylinder 2 on both the upper and lower surface.
     
  3. ASRDogman

    ASRDogman Senior Member

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    Likely, you'll need a new engine, or remanufactured one.
    Running low on oil is NEVER good for the engine.
    And the coolant passage blocker, makes it worse.
    Count on replacing the radiator, thermostadt, and possible the water pump, and
    heater core. :(
     
    #3 ASRDogman, Dec 28, 2023
    Last edited: Dec 28, 2023
    Brian1954 likes this.
  4. Mendel Leisk

    Mendel Leisk Senior Member

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    What was the miles on the car when you got the code, and had that work done?

    At that time you had codes that invariably point to already blown head gasket, and the damper between engine and transaxle broken.

    If you had a diagnosis of lung cancer, would quitting smoking cure you?
     
    #4 Mendel Leisk, Dec 28, 2023
    Last edited: Dec 28, 2023
  5. donzoh1

    donzoh1 Active Member

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    I think you're right that the head gasket might have been compromised by the earlier EGR problem. I think I remember doing a leak down test when the damper plate failed but not sure on that and wondering whether that would've shown the problem. Combustion gas bypass between 1 and 2 might have caused the 42 mpg which spiked to 48 mpg with the short lived liquid gasket fix? Basically the problem would have been present for 25K miles with no codes or symptoms except maybe excessive crankcase pressure.
     
  6. donzoh1

    donzoh1 Active Member

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    I'd probably do a JDM or junkyard motor (maybe $2K or $350 respectively) if the head gasket replacement doesn't do the trick. I basically will have $300 in parts and 40 hours of time that I usually spend watching TV otherwise. I'm going to thoroughly flush the cooling system which I'm hoping will get any foreign matter out.
     
  7. ASRDogman

    ASRDogman Senior Member

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    If you're going to spend that much for a used engine, go to hybrid pit.
    You can get a remanufactured engine, which is basically a new engine.
    With a guarantee.

     
    #7 ASRDogman, Dec 30, 2023
    Last edited: Dec 31, 2023
  8. donzoh1

    donzoh1 Active Member

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    Interesting. Yeah, I've been seeing the JDM motors with around 40K for 2000 or so. reman if good quality would probably be superior. Would consider that. This 2013 is probably gonna need some HV battery help as well as it's in the 60 percent range and I think at 230K miles it's the original OEM item.
     
  9. ASRDogman

    ASRDogman Senior Member

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    You don't know what you're getting with a jdm motor. And you don't know if it's a real
    jdm motor or someone saying it is, but it's just a used cleaned up motor.
    Then you might have the same issue you have now, in days or weeks or months.
     
    donzoh1 likes this.
  10. rjparker

    rjparker Tu Humilde Sirviente

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    . First your profile says 2004 but you are posting in gen3 and talking about egrs gen2 does not have.

    Typically you run out of oil due to bad rings, scored cylinders or not. Sounds like you are somewhere through the hg replacement process but that’s not clear as well.

    Rebuilt engine is the long term solution.
     
  11. donzoh1

    donzoh1 Active Member

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    I have a 2007 and 2013