Hybrid system overheat, high pitched sound while accelerating

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by sbweave, Jun 11, 2018.

  1. sbweave

    sbweave New Member

    Joined:
    Jun 11, 2018
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    Location:
    Minnesota
    Vehicle:
    2010 Prius
    Model:
    II
    Hi all,

    I have a 2010 Prius II with about 115,000 miles on it. The other day, I was driving from Texas to North Carolina when, towards the end of my drive, the hybrid system overheat warning came on. I was in the middle of nowhere with no service, so I had to keep driving. After about 5 minutes, the warning light shut off and the car still sounded like it was running alright so I finished the drive (another 30 minutes).

    This morning when I took it out for a quick run into town this morning, whenever I accelerated there was a high pitched whirring sound coming from the engine. I'm worried I really messed something up by continuing to drive the car after the light came on.

    Does anybody know what might be going on and if there's a way I can diagnose the problem? I have really limited experience trying to troubleshoot repair cars, but I'd really like to get better. Any help would be greatly appreciated!
     
  2. FuelMiser

    FuelMiser Active Member

    Joined:
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    Location:
    Monument, CO
    Vehicle:
    2016 Prius
    Model:
    Touring
    There are two independent cooling systems on the Prius: one for the gas engine and another for the electric drive system. Each has a coolant reservoir with (normally) Toyota pink coolant visible. The gas engine coolant tank is on the left side of the bay, and the electric system coolant tank is on the right side. First step, verify the coolant level in each reservoir using the visible MIN/MAX markings on the side of each tank. Second step, for the electric reservoir, when the car is in Ready mode, there should be some ripples visible in the fluid in the reservoir with the cap off indicating the circulation pump is working. Since you got "hybrid system overheat" I believe that would be the coolant system for the electrical side, so focus there...
     
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  3. Raytheeagle

    Raytheeagle Senior Member

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    Location:
    Bay Area, California
    Vehicle:
    2019 Prius Prime
    Model:
    Prime Plus
    Welcome to Prius Chat (y).

    Some questions:

    • In addition to the words you posted, were there any dash lights displayed?
    • How long have you owned your Prius and has the IPM software flash been done?
    • Do you have access to a code reader, which will probably be Techstream?
    • How is the coolant level in the inverter coolant loop?
    • Are there any odd smells?
    • Have you checked or cleaned the hv battery fan?
    • Ever heard the hv battery fan run in the back?
    • Have you moved from Minnesota as your profile states?
    Good luck and keep us posted (y).
     
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  4. sbweave

    sbweave New Member

    Joined:
    Jun 11, 2018
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    Location:
    Minnesota
    Vehicle:
    2010 Prius
    Model:
    II
    Hi there,

    Aside from what I posted before, there were no other warning lights. I got it inspected, and the coolant levels were all good, as well as the flow for the coolant. There are no odd smells. When I took it in, the guys at the shop I took it to (CarSpec in MN) said that the radiator was pretty clogged with stuff, and since I was driving so far that may have been what caused the overheat. So, they removed the radiators, cleaned them, and put them back in.

    That was two days ago. Today, all of a sudden the car started making a horrible rumbling noise (coming from the driver's side of the engine) while I was decelerating under 45 MPH. I made it home, but as I pulled in to my driveway the brakes started to rumble/lurch a bit, and all of a sudden a "Check Hybrid System" warning popped up as I was stopping.

    Do you have any idea what might be going on? I just had to drop 600 dollars on the radiator issue, and this car seems like it's about to break my damn bank.
     
  5. Raytheeagle

    Raytheeagle Senior Member

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    Vehicle:
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    Model:
    Prime Plus
    Thanks for the replies :).

    Some additional questions ;):
    • You seem like the domestic man of mystery (TX to NC now back in the Minneapolis/ St. Paul area all the while having this issue). Is the Prius located in the twin cities area?
    • Did you have the inverter software flash done?
    • Do you have a way to read the codes (like Techstream) or know someone who does?
    • How is the level of coolant in the inverter reservoir?
    I’ll tag some members in MN that might be able to help:

    @strawbrad ,@farmecologist , @john1701a

    Good luck and keep us posted (y).
     
  6. Mendel Leisk

    Mendel Leisk Titanic Social Director

    Joined:
    Oct 17, 2010
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    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Get a Toyota dealership to check the codes and propose a course of action. It should be about $100 at most. For sure get the codes from them too, and post.

    If it's the inverter it might be covered under warranty extension from Toyota??
     
    Raytheeagle likes this.
  7. sbweave

    sbweave New Member

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    Location:
    Minnesota
    Vehicle:
    2010 Prius
    Model:
    II
    Yeah my work kind of takes me all over the place! It is located in the Twin cites. I don't think I had an inverter software flash done, and I don't have a way to read the codes. Inverter coolant levels are good!
     
  8. Mendel Leisk

    Mendel Leisk Titanic Social Director

    Joined:
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    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    You can spend $600 plus having someone fuss with the radiators, but investing $100 getting a dealership with Techtream and a direct line to Toyota regarding warranty work: that's out of the question? I'm outa here.
     
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