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How to test water pump

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Jacob Bonner, Apr 3, 2019.

  1. Jacob Bonner

    Jacob Bonner Member

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    Feb 7, 2019
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    Vehicle:
    2012 Prius
    Model:
    Two
    I wrote a post about a month or two ago about cylinder misfires/knocking and possible blown head gasket. I am now suspecting that my water pump is bad (and probably is the cause of the possible blown head gasket). I am still having the P0301 & P0302 codes, but now I have the P0403 (EGR code - I still need to clean out the EGR.. on my to-do list) as well as a P148F. I cannot find much about the P148F code, other than a post on this forum regarding a faulty water pump. I also had trouble heating my car this winter, so it seems plausible to me that the fault lies with the pump. The car has 174,400 miles on it, so I'm thinking it's time for the water pump to have gone anyway.

    What I would like to know is how exactly do I test to see if the water pump is faulty without software such as Techstream? I have ordered the Bluedriver scan tool, but I don't know if that will be much help with this. Is there a way to turn on the water pump (with it unbolted, but still connected electrically) without starting the ICE?

    Thanks
     
    #1 Jacob Bonner, Apr 3, 2019
  2. Raytheeagle

    Raytheeagle Senior Member

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    Vehicle:
    2019 Prius Prime
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    Prime Plus
    I guess one way to do it is to see the temperature that the engine loop gets to and how fast.

    Since the pump is magnetically driven, there are no overt ways to tell, other than the code. I preventatively replaces ours at 175 k miles and there was noticeable resistance in the impeller when compared to the Aisin pump that went in.

    I have @The Critic ’s preventatively replaced water pump too and there was resistance in his impeller with 180k miles or so on it.

    So I’d vote to replace it(y).
     
    #2 Raytheeagle, Apr 3, 2019
    SFO and Jacob Bonner like this.
  3. tankyuong

    tankyuong Senior Member

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    Just have a scan gauge and constantly monitor the temps
     
    #3 tankyuong, Apr 4, 2019
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