Super deep-cleaned EGR cooler: Odd! Is this normal?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by franksrental, Jan 11, 2025 at 12:49 PM.

  1. franksrental

    franksrental Junior Member

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    Hello,
    thank you in advance for replying.
    I super deeply cleaned my EGR cooler by spraying over and over, leaving it overnight in cleaning fluid, pressure washing, etc. Almost 2 days of work off an on.
    End result. Seems like new. But inside I can barely see the light shine through and only from a certain section and at a certain angle of the cooler. The rest seems to be black. Is that normal? Or I have some sludge still stuck deep into it? I was expecting to be see through from every 'hole' in it.
     
  2. ASRDogman

    ASRDogman Senior Member

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    What did you use to clean it? Oven cleaner is the fastest and easiest.
    It will "eat" the carbon.... It should be shinny, and moving the light around you should
    be able to see through each slot.

     
  3. Brian1954

    Brian1954 Senior Member

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    It sounds like you only got the cooler partially cleaned.

    Is this the first time you cleaned it? How many miles on the car?
     
  4. Tombukt2

    Tombukt2 Senior Member

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    Yes as long as you can run brown or blackish fluid out of it every time squirt some water through the other side you see the brown but first runs out until that stops You've got a blob in there I've got two coolers here that will never stop doing that they may never come clean they've been soaking for weeks and days I would have thought I would have ate the metal by now nope