1. Attachments are working again! Check out this thread for more details and to report any other bugs.

High Coolant Temperature Warning Light

Discussion in 'Prius v Care, Maintenance and Troubleshooting' started by Carlton W Terry, May 23, 2024.

  1. Carlton W Terry

    Carlton W Terry Junior Member

    Joined:
    Feb 22, 2019
    39
    13
    0
    Location:
    Orange, CA USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    I recently had a problem where I have been burning out and ran out of oil because of it. I had to replace my spark plugs and 2 ignition coils. It's been a week and while on the freeway for a moment, the
    High Coolant Temperature Warning Light came on for about 3 minutes.. I got off the freeway, where there was a gas station, and checked the oil, coolant, and after cleaning my windows, for about 15 minutes, I turned the car back on and the light turned off. After 3 miles of driving home, It did not turn back on.

    I think I need to go back to my mechanic but it's night so I was wondering if anyone else had the same problem.
     
  2. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    7,873
    4,652
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    Lots of people have had similar problems with this engine and gen3 models. I would take it to hybridpit. At minimum, you might have a bad water pump but maybe not if the head gasket has blown.

    In reality the oil burning followed by running out of oil followed by overheating means you need an engine or get rid of the car.
     
    Carlton W Terry likes this.
  3. Carlton W Terry

    Carlton W Terry Junior Member

    Joined:
    Feb 22, 2019
    39
    13
    0
    Location:
    Orange, CA USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    Do you mean a mechanic? OMG, no. :(
     
  4. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

    Joined:
    May 12, 2018
    7,109
    6,661
    1
    Location:
    Pennsylvania
    Vehicle:
    2018 Prius c
    Model:
    Two
    These are warnings of serious problems- the engine is not likely to last a lot longer. Might already be time for a full replacement.
     
    Carlton W Terry likes this.
  5. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    55,303
    38,581
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Anymore info on that, say misfire codes?
     
    Carlton W Terry likes this.
  6. Georgina Rudkus

    Georgina Rudkus Senior Member

    Joined:
    Sep 15, 2018
    3,146
    2,194
    0
    Location:
    Taylors, SC
    Vehicle:
    2012 Prius v wagon
    Model:
    Two
    Sounds like a sticking or slowing rotor on the electric water pump.
     
    Carlton W Terry likes this.
  7. Carlton W Terry

    Carlton W Terry Junior Member

    Joined:
    Feb 22, 2019
    39
    13
    0
    Location:
    Orange, CA USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    There was a check engine light code, but I don't have that info in front of me.
     
  8. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    55,303
    38,581
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Do you know which cylinders the ignition coils were changed on? Where I'm going:

    It's common for gen 3's and Prius v's which are mechanically similar, to have head gasket failure, somewhere between 150K~200K miles. Codes that often manifest are for "misfire":
    P0300 (general misfire code)
    P0301 (misfire cylinder one)
    through
    P0304 (misfire cylinder four)

    Typically the head gasket failure is at the exhaust side, between cylinders one and two, allowing coolant to seep into either cylinder, though more typically cylinder one.

    What's the miles on it?

    Has the EGR (Exhaust Gas Recirculation) system, including intake manifold, ever been cleaned?


    It's fairly common for these head gasket failures to be misdiagnosed, and unecessary spark plug and coil replacements done, because it's easy and profitable for mechanics.

    The other issues:

    runaway oil consumption, likely due to low-tension piston rings Toyota used, till partway through model year 2014 with the Prius hatchback. Plus drain holes in the pistons that are prone to clog. Prius v also finally revised the low-tension piston rings, but your 2012 will have the low-tension rings for sure.

    electrically driven water pump, that is prone to failure, somewhere between 100K~150K miles.
     
    #8 Mendel Leisk, May 23, 2024
    Last edited: May 23, 2024
    Carlton W Terry likes this.
  9. Carlton W Terry

    Carlton W Terry Junior Member

    Joined:
    Feb 22, 2019
    39
    13
    0
    Location:
    Orange, CA USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    There were misfires on 1 and 3. I'm at about 193k. I bought it at 130k. The previous owner kept amazing reports, and I am sure he never changed or cleaned any of those things. I will say something about it to my mechanic. It's a Pruis v5 if that matters.
     
  10. ttou68

    ttou68 Active Member

    Joined:
    Sep 9, 2017
    345
    203
    0
    Location:
    40509
    Vehicle:
    2010 Prius
    Model:
    III
    I would see engine high temperature, and oil burning are 2 separate issues. Not saying oil burning due to high engine temperature is not related...
    Likely you have a failed engine water pump, and possibly a bad thermostat...
    although I haven't seen a bed thermostat from this generation of Prius, but I wouldn't rule out the possibility and would replace it with water pump...

    As for loss of engine oil...
    I would check for oil leaks externally, if non or very light oil leak found. Then I would look into piston rings and valve seals...
    I've replaced few valve seals, and seen greatly reduced oil consumption, but not to say you didn't have bad piston rings ..

    Also, I wouldn't rule out the possibility of bad head gasket because of engine miss fire, but it also can be the end result of clogged EGR circuit if they haven't been maintained...

    Just my 2 cents, but I would definitely check for fault codes first and address it accordingly...

    Good Luck!

    Posted via the PriusChat mobile app.
     
    #10 ttou68, May 24, 2024
    Last edited: May 24, 2024
    Carlton W Terry and Brian1954 like this.
  11. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    55,303
    38,581
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Your EGR components, the cooler and valve, will be packed with carbon, reducing overall flow. The EGR passages in intake manifold that feed exhaust gas to individual cylinders are about 1/4” ID, can totally clog, completely sealing of what remains of the exhaust gas supply.

    then engine runs hot, head gasket fails, allowing coolant to seep into cylinders, engine struggles to compress the uncompressible coolant, “misfires”.

    toyota screwed the pooch with Gen 3 EGR introduction, didn’t test it sufficiently, and is dodging responsibility. For owners, the only workaround is an arduous disassemble and clean of the mess, say every 50k.
     
    Carlton W Terry likes this.
  12. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    7,873
    4,652
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    This car burns oil so bad it ran out of oil. Give me a break.
     
  13. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    55,303
    38,581
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Yes, it did that, too. Clogged EGR and low-tension piston rings can work in concert.
     
    Carlton W Terry likes this.
  14. Carlton W Terry

    Carlton W Terry Junior Member

    Joined:
    Feb 22, 2019
    39
    13
    0
    Location:
    Orange, CA USA
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    TYVM!