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Overheating light comes on for 1 to 2 mins goes off..

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by StevenAlabama, Nov 13, 2022.

  1. StevenAlabama

    StevenAlabama New Member

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    Three
    My overheating light comes on stays on for less than 2 minutes goes off. It's been doing this for well over a year. When it first started doing it it would be about every month every 3 weeks kind of like clockwork
    .
    Then I'll begin to notice it was losing coolant from the reserve...
    The EGR throttle body and all that was cleaned, the heat exchanger was dented so it was replaced as well..
    After this it started coming on more often I would say every couple of days then it started coming on every day and it was losing coolant from the reserve tank which was being blown out.


    I had the thermostat replaced they went over the hoses, tested the head gasket.. and replaced the cap on the reserve tank.

    Now it's still coming on but about every 2 days so far very little coolant if any is lost.


    Any help in this matter will be greatly appreciated because it's driving me crazy. Toyota told me as long as the overheating light doesn't stay on it goes off that's normal before that was before was losing coolant..

    Anybody have any issues similar to this? Thank you
     
  2. Tombukt2

    Tombukt2 Senior Member

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    Yep generally it's a head gasket failing on the generation 3 etc etc many have been through this and many are going through it I just finished with this
     
  3. tankyuong

    tankyuong Senior Member

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    head gasket
     
  4. ASRDogman

    ASRDogman Senior Member

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    You don't state how many miles you have on it.
    I would suspect the water pump. You can purchase just the impeller and replace that.
    A lot less money.
    And the engine has been overheating, which is not good. Hopefully, you don't have a warped head.
    But it's likely the head gasket is failing.
    You need to get to a good place that knows about the Prius...

     
  5. rjparker

    rjparker Tu Humilde Sirviente

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    Change the pump first. It is a good move even if the head gasket is history. Use only dealer supplied oem; counterfeits with Toyota packaging are all over ebay and amazon. Normally the hg causes random first start severe rattling weeks or months before it causes lost coolant.

    Future fyi... The coolant light will never come on without an underlying issue, coolant loss is never normal and dealer mechanics occasionally give bad advice based on an individual's level of experience. Normal combustion gas or leakdown tests are not definitive hg tests on a gen3 engine. Pressurized coolant combined with a quality borescope can be diagnostic in the hands of an experienced tech.

    There may be one Toyota Master Mechanic at a dealer and she might be working on my car, not yours. Service advisors often know less than the oil change guy and usually were never skilled mechanics.
     
    #5 rjparker, Nov 14, 2022
    Last edited: Nov 14, 2022
    CR94 likes this.
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    What’s the miles on it, and what miles was the EGR cleaned? Intake manifold cleaned as well? Any chance of a stop-leak product in the coolant?