2011 prius overheating

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Michaelz28, Dec 2, 2025 at 8:17 PM.

  1. Michaelz28

    Michaelz28 New Member

    Joined:
    Nov 29, 2025
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    Location:
    Los angeles.
    Vehicle:
    2011 Prius
    Model:
    Five
    So i have a 2011 prius i have overheating at 240000k miles i had swap the radiator water pump thermostat and still no fix... so I swap the engine to a JDM engine... car is still over heating i saw that the passenger fan was working, but the driver's side wasn't so I swapped the fan and the radiator I noticed when the heater and the ac is on or when the car is driving.Uphill is when the light comes does any one have any other clues I was thinking about swapping the temperature sensor ... i don't know what this problem could be.If I let the car sit for a day or two, the engine check light turns off car runs fine and then the temperature light comes on again and repeats the process... po117 and p148f are the codes that my scanner is reading
     
    #1 Michaelz28, Dec 2, 2025 at 8:17 PM
  2. Brian1954

    Brian1954 Senior Member

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    Location:
    South Central PA, USA
    Vehicle:
    2011 Prius
    Model:
    III
    I would have responded to your post, but I guess I did not see it earlier.

    The high coolant temperature warning light on the dashboard can be activated by two different coolant temperature sensors. One is the obvious coolant sensor located in the engine. The other is a coolant temperature sensor for the exhaust heat recovery system. Take a look at this thread, https://priuschat.com/index.php?posts/3549096

    Have you used an OBD2 scanner to monitor the engine coolant temperature? If so, you were probably looking at the temperature sensor that is located in the engine. You should use a scanner to also monitor the temperature sensor for the exhaust heat recovery system.

    You stated that you replaced the engine coolant water pump. Did you use a new OEM pump purchased from a Toyota dealership, or did you buy an aftermarket pump?

    Did you use a Gen 3 or Gen 4 JDM engine when you did the engine swap?
     
    #2 Brian1954, Dec 7, 2025 at 8:59 AM
    BiomedO1 likes this.
  3. Mendel Leisk

    Mendel Leisk MMX GEN III

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    Oct 17, 2010
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    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    How long have you had it?
     
    #3 Mendel Leisk, Dec 7, 2025 at 10:02 AM
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