What Is This Mystery Hole?

Discussion in 'Bonneville' started by Zwniana, Sep 20, 2025.

  1. Zwniana

    Zwniana New Member

    Nov 11, 2024
    12
    3
    Philadelphia, PA
    #1 Zwniana, Sep 20, 2025
    Can someone help me identify this mystery hole.

    IMG_9158.jpeg
     
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  2. joe mc donald

    joe mc donald Joe
    Subscriber

    Dec 26, 2014
    16,012
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    slough / burnham
    #2 joe mc donald, Sep 21, 2025
    @Zwniana Not got a scuby. Sure you haven't lost a bolt from there.
     
  3. Regit nogara

    Regit nogara Active Member
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    Apr 22, 2025
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    North, North Wales
    #3 Regit nogara, Sep 21, 2025
    What is the bike? Wider view maybe?
     
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  4. Zwniana

    Zwniana New Member

    Nov 11, 2024
    12
    3
    Philadelphia, PA
    #4 Zwniana, Sep 22, 2025
    It is a 2024 bonneville. Seems like a vent hole for something. It’s below the oil pan.
     
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  5. 243jimb

    243jimb Member

    Nov 27, 2018
    13
    8
    Canada
    #5 243jimb, Sep 22, 2025
    It's the "weep" hole for the water pump.
     
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  6. Zwniana

    Zwniana New Member

    Nov 11, 2024
    12
    3
    Philadelphia, PA
    #6 Zwniana, Sep 22, 2025
    ahhhhh this makes more sense. thank you.
     
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  7. RickM46

    RickM46 Active Member

    Oct 12, 2023
    75
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    #7 RickM46, Nov 16, 2025
    OK, I'll bite; so what's a weep hole for the water pump?
     
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  8. 243jimb

    243jimb Member

    Nov 27, 2018
    13
    8
    Canada
    #8 243jimb, Nov 16, 2025
    It's the same as on a car water pump, there is usually a tiny amount of coolant that escapes between the shaft bearing and the housing as it heats and cools. Some pumps never leak a drop whilst others do.
     
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  9. RickM46

    RickM46 Active Member

    Oct 12, 2023
    75
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    US
    #9 RickM46, Nov 17, 2025
    Yes, that brings back memories; should have remembered; changed the water pump on my '73 Plymouth Duster Slant Six enough times and now recall the weep hole - wondered then what that hole was for.
     
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