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2015/123000 mile/Well Maintained/ Head Gasket Going?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by philr, Aug 21, 2024 at 3:48 AM.

  1. philr

    philr Junior Member

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    I have been following the recommended maintenance suggestions to a T (even early water pump replacement and the EGR cooler cleaning) with the expectation that the head gasket on my 2015/123k mile prius would not fail. But I think it's leaking.

    Most of my driving is commuting and city driving, but last week I took an 8hr/500mi drive to visit family and the next morning at start-up the engine shook/cylinder not firing and then quickly cleared up. I drove the car during my visit without further problems and returned home another 8hr/500mi - no problems.

    I inspected the car when I got home and noticed the coolant jug fluid level was down about 1/4 inch from the full mark - all other fluids were correct. I have not seen any leaks or evidence of leaks. Could this be the beginning of a head gasket failure?
     
    #1 philr, Aug 21, 2024 at 3:48 AM
    Last edited: Aug 21, 2024 at 4:01 AM
  2. bisco

    bisco cookie crumbler

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    possible, but highly unlikely. fill the coolant and keep an eye on it.

    occasional startup misfires are common to the beast. coolant may be low or may have always been there, unless you have been watching it. you might lose a bit under normal circumstances as well.
     
    #2 bisco, Aug 21, 2024 at 8:20 PM
  3. Mendel Leisk

    Mendel Leisk Senior Member

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    It might be. Monitor the coolant level (say put a strip of masking tape on the reservoir, and mark current level with a Sharpie pen). Also obviously, see how the cold-starts go.
    You cleaned the EGR passages in intake manifold also?
    What miles did you do the cleaning at?
     
    #3 Mendel Leisk, Aug 21, 2024 at 9:17 PM
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