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Gen 4 Coolant leak

Discussion in 'Gen 4 Prius Main Forum' started by Moloki, Nov 29, 2021.

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  1. Moloki

    Moloki New Member

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    2016 Prius
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    Two Eco
    My Gen 4 is losing coolant to about 1 inch in the reservoir. No codes, but no heat is the signal. No obvious leak, no drip. Mileage is steady at 48-54 mpg. Runs smoothly. No white smoke. Have smelled sweet coolant smell twice. Ran pressure tests, hot and cold with it holding pressure, boroscoped each cylinder at local Prius shop
    Ideas?
     
  2. bisco

    bisco cookie crumbler

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    how much does it lose in 24 hours?

    is it different if you drive or don't drive?

    how many miles on her?
     
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  3. RRxing

    RRxing Senior Member

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    Had mine repaired under warranty. You might have the same issue.
     

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    V Sport Wagon, Reypac24 and dig4dirt like this.
  4. Ozark Man

    Ozark Man Member

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    I discovered mine was a little low when I got it home from the dealer . I bought it certified with 22,500 miles. I probably added about a pint and so far after about 1500 miles it hasn't went down any more that I can tell. Hopefully if there was a problem it is fixed and they just neglected to fill it back up.
     
  5. MalachyNG

    MalachyNG Active Member

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    If your shop couldn't find a leak are you sure it's not just you checked when it was too warm or cold? It the coolant in the reservoir goes up and down with temperature and use so as long as it's between the full and low lines you may not have a leak. Unless you mean it is 1" below the low line or it is losing 1" in a certain timeframe.

    Did they check all the lines for any leaks? You can usually tell if there's a pink crust near a line or connection, if it's a small enough leak it may mostly evaporate and leave residue instead of a puddle under the car. The weak heat is concerning. If you aren't getting answers from your local shop you may need to stop by a Toyota dealership
     
  6. DOHCtor

    DOHCtor Member

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    Thread revival.. at the dealership where i work, we change way too much exhaust front pipes/heat traps.. they leak in the exhaust so no apparent coolant leak is detected but it does smell sweet.
     
  7. Prius2016excel

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    I’m another victim I’m sad to report, see: 2016 - complete power loss / breakdown | PriusChat

    Out of interest DOHCtor do you know if the car is ok to drive indefinitely with this happening? I’m topping up the coolant as necessary and get white smoke out the back under heavy acceleration. Thanks.
     
  8. jteran5

    jteran5 Active Member

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    Toyota should actually do a recall and get these replaced.... I have a 2019 and while I don't have symptoms (that I know of), I'm worried that I might experience it after the emissions warranty expires. I know it happened to someone here already where she had to pay around 2k out of pocket because she was past the warranty but it was for this exact failure.

    Posted via the PriusChat mobile app.
     
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  9. Mukunda

    Mukunda Junior Member

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    starts with P148F
    then apply T-SB-0135-19 - replace Front Exhaust pipe.
    problem recurs, and then dealer does some patch work.
    once warranty of your Engine expires, they say engine gone needs to be replaced.

    this is what my experience from 2016 Prius
    Problem started at 43K, Engine died at 51K on 1st March 2023.
    Toyota is denying any recalls / Manufacturing defect.
    Reported to National Highway safety
     
    bisco likes this.
  10. Seffy

    Seffy New Member

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    IMG_7298.jpeg IMG_7297.jpeg IMG_7296.jpeg
     

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  11. V Sport Wagon

    V Sport Wagon Member

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  12. Mendel Leisk

    Mendel Leisk Senior Member

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    @Seffy, what’s the story?
     
  13. Seffy

    Seffy New Member

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    I made a text post and got a message that it had to be reviewed by admin since it was my first post. Thats the last i saw of it! Basically, I have a rebuilt title Toyota and had to bypass the heat exchanger due to a leak. This is just a photo for folks to see what it looks like. Just connect those two “holes” Pretty with a loop of coolant hose.
     
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  14. Doug McC

    Doug McC Active Member

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    Did it still have the original coolant in it?
     
  15. Gary Rieger

    Gary Rieger Junior Member

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    the dummy light is far right-side of dash instrument panel and is a 1/4 inch in size even more frustrating is the fact the main info section that tells you to stop and have coffee along with a ringing bell is not a part of the overheating or low oil warning system!!!
     
  16. sylvaing

    sylvaing Active Member

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    If someone runs Hybrid Assistant as part of their usual routine when driving, would the engine coolant temperature be any indication that something is wrong? I'm guessing the coolant temperature wouldn't increase as the coolant is dumped into the exhaust instead of recirculating back to the engine to cool it (and warm the coolant in the process).