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Overheating going up inclines is it time for a new thermostat?

Discussion in 'Gen 3 Prius Main Forum' started by bootsncats24, Sep 3, 2020.

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  1. sam spade 2

    sam spade 2 Senior Member

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    Not unless it gets well above 212 it won't.
    And not if the pressure cap is not holding ANY pressure it won't either.
    The "vent" hose likely is below the engine where you won't notice.

    And to repeat a previous point:
    The high temp alert should NOT come on if the engine temp is only 212.
    That is well within the "normal" operating range.
     
    #21 sam spade 2, Sep 4, 2020
  2. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    I'm just guessing but if there's flow (as seen in the bottle) and coolant temp is below 212, then there isn't as great a chance that you're going to have an over-temp condition.
     
    #22 ETC(SS), Sep 4, 2020
  3. sam spade 2

    sam spade 2 Senior Member

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    IF.....there is coolant flowing AND the temp is below 212......there is ZERO chance of a legitimate "over-temp condition".
    By definition.
     
    #23 sam spade 2, Sep 4, 2020
  4. bootsncats24

    bootsncats24 Junior Member

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    Does the high temp warning have any other meaning except high engine temp? I was watching my temps through my OB2 port reader saw 212 then saw the high temp warning light.
     
    #24 bootsncats24, Sep 4, 2020
  5. orenji

    orenji Senior Member

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    Take it to Hybridpit in Buena Park. Have you had the coolant changed out in both systems, Inverter and ICE?
     
    #25 orenji, Sep 4, 2020
  6. sam spade 2

    sam spade 2 Senior Member

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    Nope. That's it.
    Is there more than one temp sensor.......I don't know.
    On a conventional vehicle there is only one.
     
    #26 sam spade 2, Sep 5, 2020
  7. bootsncats24

    bootsncats24 Junior Member

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    Thanks guys. Im definitely going to need find somewhere else to take my car. Took it to the shop mechanic doesn’t seem to have a clue what’s causing it to overheat. He did a stress test and checked all the fans and it was fine. He think it’s overheating going up an incline because I don’t have the under tray below the bumper.
     
    #27 bootsncats24, Sep 5, 2020
  8. Grit

    Grit Senior Member

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    Key info hidden is the distance driven uphill. If it’s 3 miles of uphill at 70mph then I can see overheating. It it’s quarter mile and overheat then something is wrong.
     
    #28 Grit, Sep 5, 2020
  9. jerrymildred

    jerrymildred Senior Member

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    Aha! That could be it if it's used to direct air through the radiator.
     
    #29 jerrymildred, Sep 6, 2020
  10. sam spade 2

    sam spade 2 Senior Member

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    Sure, that could be a factor.
    BUT.....for the third time, at least......coolant temp of 212 does NOT indicate an "overheat" condition.
    Maybe the temp sensor has gone bad.
     
    #30 sam spade 2, Sep 6, 2020
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  11. bootsncats24

    bootsncats24 Junior Member

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    Planning on having another shop check the temp sensor. When I asked the mechanic why he thought the temp sensor was coming on even though 212 the engine is not over heating. His response was it’s warning you that it’s about to overheat a check engine would come on if it’s overheating.

    The incline was a couple miles long however I’ve gone up that same incline plenty of times in the same weather conditions without it heating up.
     
    #31 bootsncats24, Sep 6, 2020
  12. sam spade 2

    sam spade 2 Senior Member

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    TOTAL BS.
    You definitely need a different mechanic.
     
    #32 sam spade 2, Sep 6, 2020
  13. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    +1.
     
    #33 ETC(SS), Sep 7, 2020
  14. bootsncats24

    bootsncats24 Junior Member

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    Found a different shop. They did a pressure test on the cooling system and tested the engine for a blown headgasket. Both test came back with no issues. They recommended I changed the radiator. Had the radiator changed and it’s the same issue still.

    A solid high temp warning light comes on. I’m wondering if that temp sensor is going bad. According to the documentation I have at 210F the light should not be coming on. It’s suppose to come on at 230. If I’m understanding correctly the high temp light is suppose to come on blinking when the temps reach 230 stay solid when the temps keep climbing.

    Since my high temp warning light comes on at 210 it leads me to believe that the sensor might be going bad. I don’t understand why it would come on when the cars not overheating.
     
    #34 bootsncats24, Sep 10, 2020
  15. ChapmanF

    ChapmanF Senior Member

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    If you're getting the temperature from an OBD reader then you are seeing what the ECU thinks the sensor is reporting.

    Out of curiosity, what are the reported inverter and MG temperatures at the same moment?
     
    #35 ChapmanF, Sep 10, 2020
  16. bootsncats24

    bootsncats24 Junior Member

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    It says inverter coolant temp 54
    Inverter MG2 Temp 125F. I think I’m reading the ones.

    With the temps at 210 should the high temp light even come on as solid? My temps were slowly climbing but I was also going up an incline. I can drive it all day hard and it’ll be fine but once I hit an incline for a couple miles and am going 70 plus the light will come on as soon as the temps hit 210.
     
    #36 bootsncats24, Sep 10, 2020
  17. cnc97

    cnc97 Senior Member

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    From experience with mine, I can tell you that the cooling fans come on at around 200 degrees, and kick off when they drop to 190 (203 and 193 on my scanner app). The highest temp I have ever seen was 204.5, and that was on a 5.5% grade coming home from Chattanooga, TN.

    I’d venture that the water pump is not able to circulate at the higher temps, and the hotter the car gets, the slower it spins. It should do the opposite. If the integrity of the head gasket has been checked, that’s where I’d look after the switches.
     
    #37 cnc97, Sep 10, 2020
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  18. sam spade 2

    sam spade 2 Senior Member

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    NO. For the third or fourth time. NO.
     
    #38 sam spade 2, Sep 10, 2020
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  19. bootsncats24

    bootsncats24 Junior Member

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    I have a brand new factory water pump in the car. Should I have the fans rechecked? With a new water pump I don’t know how the water pump wouldn’t be running correctly.
     
    #39 bootsncats24, Sep 10, 2020
  20. bootsncats24

    bootsncats24 Junior Member

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    I understand that. I’m trying to find out why the light is coming on. Would you continue to drive it and keep an eye on the temps manually?
     
    #40 bootsncats24, Sep 10, 2020
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