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08 Prius Three Way Coolant Valve replaced then Inverter Coolant Pump Broke

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by RGBrun, May 28, 2021.

  1. RGBrun

    RGBrun Junior Member

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    Vehicle:
    2008 Prius
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    Four
    I have an 08 Prius with 159k miles. I got a check engine light with error code P1121. Had the three way coolant control valve replaced for ~$700. After getting the car back, on start-up, I could hear the sound of fluid rushing around that I had not heard before (sounded like it could have had air mixed in with it). A day after the three-way valve repair, I got the red triangle of death and now the mechanic is telling me the inverter coolant pump needs to be repaired for ~$500. Could these two issues be related - Could the first repair have been done improperly causing the inverter coolant pump to fail?
     
  2. dolj

    dolj Senior Member

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    It is just a coincidence.

    More than likely it is actually air in the engine cooling system (quite separate from the inverter cooling system) that is causing the gurgling sounds. You need to ensure you check the radiator every day for a week and top up as required. Take the top front engine bay cover off and leave it off until you're done with the daily checks.

    Out of interest, why does the mechanic conclude the inverter coolant water pump has failed?
     
  3. TMR-JWAP

    TMR-JWAP Senior Member

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    The 3 way valve is in the engine coolant loop. The noise you hear is, as mentioned, air in the system due to not being bled completely. As long as it's not too bad, it should eventually clear itself up. If it's a LOT of air then it could be a problem.

    The inverter cooling water loop is completely separate from the engine cooling water loop. As mentioned by dolj, how did the mechanic determine the ICWP has failed? Was it a P0A93 code? Pump not running when car is in IG-ON or READY mode? No flow in the inverter reservoir?
     
  4. jonsey1886

    jonsey1886 Junior Member

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    Location:
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    Vehicle:
    2009 Prius
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    ----USA----
    Toyota dealership technician here:

    Your failed HV cooling pump might be covered under the safety recall (Safety Recall C0U) for the HV water pumps. If so you'd get the repair for free.
    Check at the Toyota USA Lookup Safety Recalls & Service Campaigns website.

    Also the technician who fixed the engine cooling system should have properly bled the air from the system. If you want to do it at home yourself fill up the reservoir with the proper Asian Pink coolant (AISIN ACT002, Toyota/Lexus/Scion SLLC, etc) and put the vehicle into inspection mode which keeps the ICE from shutting off.
     
  5. ChapmanF

    ChapmanF Senior Member

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    Although the two components are in two completely separate coolant loops, the loops are near each other. The engine coolant hoses even cross the inverter cooling loop to get to where the thermos and three-way valve are, near the fender farthest from the engine.

    ... which means if the mechanic doing the work on the three-way valve got disoriented, it could have been possible to also disturb the inverter coolant loop by mistake.