AISIN WQT-800 inverter pump failing within a year?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Oranjoose, Nov 20, 2024.

  1. Oranjoose

    Oranjoose New Member

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    A year ago December, I posted saying a cheap inverter pump was failing after a couple months ( Any way to keep inverter pump alive once it starts croaking? | PriusChat ) , and everybody said I should replace with OEM, and so I replaced it with an AISIN WQT-800.

    11 months and merely 3000 miles later, this AISIN pump is making that hallmark wheekoo wheekoo electronic pumping sound my original Prius pump made before it failed.

    When I put in the AISIN, I bled the air out of the lines and mostly swapped the coolant (a hose clamp failed and drained most of the coolant, but I didn't drain the rest out of the bottom).

    Should I completely drain the coolant and fill with new coolant? Would that rescue this pump? I feel that this pump is failing very early for its reputation.

    If the coolant is in fact contaminated with particulates and such, would replacing the coolant do much to prevent this pump from failing, or should I just replace it (again) AND change all the coolant?

    The reservoir is turbulent in ACC mode (orange light, engine off), and the pump is making its normal hum, indicating the pump is still working. It's just begun to do the electronic croaking (I've heard it now 5 or so times) if at a stop light after driving above 50mph (at least that seems to be the pattern).
     
    #1 Oranjoose, Nov 20, 2024
  2. dolj

    dolj Senior Member

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    Just to be clear, the AISIN WQT-800 is not OEM. It is also possible that it is not a genuine AISIN WQT-800 either. Depending on where it was purchased, it could very well be a counterfeit.
    Whether you replace it is up to you but it won't likely "rescue" your pump.
     
    #2 dolj, Nov 21, 2024
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  3. Oranjoose

    Oranjoose New Member

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    I ordered it from Rock Auto and it was the model that members of this forum were recommending.

    Are you saying that once it starts making that wheekoo wheekoo struggling pump sound that it's pretty much inevitable that it's on its way out?
     
    #3 Oranjoose, Nov 21, 2024
  4. mr_guy_mann

    mr_guy_mann Senior Member

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    Do not know. I ordered a pump from the Toyota dealer 65k ago. Haven't had any problems.

    Posted via the PriusChat mobile app.
     
    #4 mr_guy_mann, Nov 21, 2024
  5. dolj

    dolj Senior Member

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    Are you sure you're hearing that sound from the pump and not the coolant control valve, which is nearby the inverter coolant pump?
     
    #5 dolj, Nov 21, 2024
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  6. T1 Terry

    T1 Terry Active Member

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    Are you sure it isn't pump cavitation? That is not only a pump killer, it can be a component kill as well. Usually caused by loss of cooling system pressure and dilution of the coolant allowing it to either boil because of temp, or because there is a restriction on the intake side dropping pressure and in turn, dropping the boiling point. Have you replaced the hoses on the suction side of the pump, they can suffer with being sucked in to the point they restrict flow, exaggerating the problem even further .......

    T1 Terry
     
    #6 T1 Terry, Nov 22, 2024
  7. Oranjoose

    Oranjoose New Member

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    My coolant control valve is indeed failing (intermittent code P1121), but does it make the same noise? My inverter pump failed summer 2023, resulting in the red triangle inverter overheat. The sound that the inverter pump was making before that sounds exactly like the sound that's happening now, and it's happening in the same scenarios (occasionally after driving over 50mph for 10 minutes and then coming to a stop).

    I haven't gotten the P0A93 code yet for a failed inverter coolant pump.
     
    #7 Oranjoose, Nov 25, 2024
  8. dolj

    dolj Senior Member

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    The CCV's common failure sound is similar to a top-loading washing machine agitating or an HDD constantly seeking (only much louder). There are quite a few posts in the Gen 2 forums where people have uploaded a sound file demonstrating the sound.

    If that's the sound you hear, it is the CCV, not the ICWP.
     
    #8 dolj, Nov 25, 2024
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