Another EGR thread

Discussion in 'Prius v Care, Maintenance and Troubleshooting' started by darknd666, Apr 1, 2026 at 12:01 AM.

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  1. rjparker

    rjparker Tu Humilde Sirviente

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    The pressure is to force drops on a borescope test. It can look fine and should either way.
     
    #61 rjparker, Apr 2, 2026 at 5:52 PM
  2. darknd666

    darknd666 Junior Member

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    Im confused by your statement? What do you mean? Are you saying it can still be the head gasket even if no drops form?
     
    #62 darknd666, Apr 2, 2026 at 6:10 PM
  3. rjparker

    rjparker Tu Humilde Sirviente

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    The pressure can hold either way
     
    #63 rjparker, Apr 2, 2026 at 6:21 PM
  4. darknd666

    darknd666 Junior Member

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    So is my test good?
     
    #64 darknd666, Apr 2, 2026 at 6:22 PM
  5. darknd666

    darknd666 Junior Member

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    Ok so Ive added a ziptie and it seems to hold at 16PSI which is from what ive tead the test pressure. Ill just keep monitoring and add pressure as it drops.
     

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    #65 darknd666, Apr 2, 2026 at 6:40 PM
  6. darknd666

    darknd666 Junior Member

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    Spark plug conditions for those curious. Left to right 1-4
     

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    #66 darknd666, Apr 2, 2026 at 7:35 PM
  7. darknd666

    darknd666 Junior Member

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    This is looking more like an EGR problem and less a blown head gasket, unless the leak is only present under heat soak cycles.
     
    #67 darknd666, Apr 2, 2026 at 7:36 PM
  8. darknd666

    darknd666 Junior Member

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    Sorry I forgot to mention if removing the EGR cooler caused enough coolant to be removed to hinder the coolant pressure test?
     
    #68 darknd666, Apr 2, 2026 at 7:39 PM
  9. ChapmanF

    ChapmanF Senior Member

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    I think what rjparker is getting at is that you can use that pressurization kit to accelerate a borescope test—by pumping up a good pressure in the system, you can make drops form faster so you have a better chance of seeing them on your borescope—but that it wouldn't be a very sensitive test to just rely on watching for a pressure drop. Tiny drops slowly leaking just might not make enough difference in the gauge pressure to notice, or to tease out from the effect of, say, ambient temperature changes during the time that you're watching.
     
    #69 ChapmanF, Apr 2, 2026 at 8:45 PM
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