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

Overheating again

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by johnnychimpo, Jun 25, 2021.

  1. johnnychimpo

    johnnychimpo Active Member

    Joined:
    Aug 21, 2007
    511
    109
    0
    Location:
    Monterey
    Vehicle:
    2010 Prius
    Model:
    Three
    Someone refresh my memory on the following
    1.fuses for water pump and how to test it all i got is a test light
    2.cooling fans and what is normal function

    the story my EGR got stuck open I will need to replace it. unplugged it moved on
    it got really hot as the EGR cooler cant deal with it stuck in open state sucking in hot exhaust all the time.
    now closed and disconnected. car pulled a code saying engine wont start so I unplugged the main white wire in the fuse box to clear the code memory. engine start runs fine it complained about the EGR but its disconnected so I can ignore that. No other codes to display. test drove it but noticed the coolant getting to 210 F.
    not normal. coolant level is normal and radiator fans are spinning so is my pump bad or fuses burned out. or the fans not working optimally. Sorry guys it is late I hope Im making sense.
     
    #1 johnnychimpo, Jun 25, 2021
  2. johnnychimpo

    johnnychimpo Active Member

    Joined:
    Aug 21, 2007
    511
    109
    0
    Location:
    Monterey
    Vehicle:
    2010 Prius
    Model:
    Three
    Slight update, I connected an spare pump that I have and it spins up so power is not a issue. coolant is still at normal levels so I think either impeller maybe maybe could me worn or thermostat is stuck or bad (how do I test if it is stuck closed.) Else fans are the last thing I can think of that is not working as they should as they do spin but not sure how fast the should be going.
     
    #2 johnnychimpo, Jun 25, 2021
  3. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,673
    38,214
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    You replaced the head gasket in February? Had you had the car long? Maybe previous owner tried stop-leak coolant product?
     
    #3 Mendel Leisk, Jun 25, 2021
  4. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,277
    15,074
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    Pot of water on the stove, easy test.
     
    #4 ChapmanF, Jun 25, 2021
  5. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,673
    38,214
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    When I did that it was after purchasing replacement thermostat. I suspended them both in the pot, brought the temp up and you could really see the difference. First off, the old one's gasket was hardened, and the edges frayed/chipped. Then, as the temp of water climbed, the old one opened sooner.

    My issue was excessive cooling when driving on a cool morning on a "weekend" freeway, not many other cars on the road.
     
    #5 Mendel Leisk, Jun 25, 2021
  6. mjoo

    mjoo Senior Member

    Joined:
    Nov 9, 2016
    1,107
    1,311
    12
    Location:
    Michigan
    Vehicle:
    2010 Prius
    Model:
    III
    Johnny has a gen4 engine in a gen3.

    How many miles on the gen4 engine?

    moto g power ?
     
    #6 mjoo, Jun 25, 2021
    Mendel Leisk likes this.
  7. johnnychimpo

    johnnychimpo Active Member

    Joined:
    Aug 21, 2007
    511
    109
    0
    Location:
    Monterey
    Vehicle:
    2010 Prius
    Model:
    Three
    Thanks but it seemed to have resolved itself. My theory here is the EGR got stuck open and it got supper hot after all it is exhaust gas going in all the time and I don't think the EGR cooler is meant to be able to cool it when it is stuck open. In any case I think it got so hot it created steam/air bubble causing flow issue once it cooled overnight it went back to liquid . this morning drove it for 40 min it got to 212 once then never went above 208 now it goes between 196 to 204 tops. let me know what you guys think. I have a long trip to Vegas hopefully i am correct here and this is a non issue.
     
    #7 johnnychimpo, Jun 25, 2021
  8. johnnychimpo

    johnnychimpo Active Member

    Joined:
    Aug 21, 2007
    511
    109
    0
    Location:
    Monterey
    Vehicle:
    2010 Prius
    Model:
    Three
    this engine I got with supposedly 10 K miles from a totalled JDM supplier I suspect true as one of the valve cover bolts looked slightly bent, I suspect from an accident.
     
    #8 johnnychimpo, Jun 25, 2021
  9. mjoo

    mjoo Senior Member

    Joined:
    Nov 9, 2016
    1,107
    1,311
    12
    Location:
    Michigan
    Vehicle:
    2010 Prius
    Model:
    III
    Is there a VIN on the engine that you can look up?

    moto g power ?
     
    #9 mjoo, Jun 25, 2021
  10. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,673
    38,214
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Yeah this. Something problematic with the coolant hose rework?
     
    #10 Mendel Leisk, Jun 25, 2021
  11. johnnychimpo

    johnnychimpo Active Member

    Joined:
    Aug 21, 2007
    511
    109
    0
    Location:
    Monterey
    Vehicle:
    2010 Prius
    Model:
    Three
    no its a JDM so VIN.
     
    #11 johnnychimpo, Jun 25, 2021
(You must log in or sign up to post here.)