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Coolant Levels

Discussion in 'Gen 4 Prius Care, Maintenance and Troubleshooting' started by JohnPrius21, Jul 17, 2022.

  1. JohnPrius21

    JohnPrius21 Junior Member

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    My 2017 Prius (in California) has almost 80,000 miles and seems to have low coolant levels. I’m not sure how to read the coolant level on the engine coolant reservoir. There looks like two levels within the same reservoir. Where should I be reading?

    I’m the original owner and have never added coolant and these pictures were taken when the car was cold. I’ve noticed it slowly dropping in the past two years. Should I simply add more coolant and monitor? Is this normal coolant loss after 5 years?

    Pictures may look weird because they were taken with a flashlight shining down onto the reservoirs.

    C05B9E41-510F-4862-AA72-1E04AA0B02BA.jpeg C20D5C57-8993-4151-8537-07FCF9978B8C.jpeg F4A6788D-F194-4D7F-8F21-5872C235A46D.jpeg
     
    #1 JohnPrius21, Jul 17, 2022
  2. Mo. J

    Mo. J Junior Member

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    Firstly, add coolant up to the "FULL" line in both reservoirs.
    You didn't get the "HIGH TEMP" light alarm on the dashboard? "CHECK ENGINE"?

    And if you don't notice any leaks, search the forum for (Exhaust heat exchanger) or (Water pump), I think these are common and likely is what you got - if there is no visible leak.
     
    #2 Mo. J, Jul 18, 2022
  3. RRxing

    RRxing Senior Member

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    See attached...
     

    Attached Files:

    #3 RRxing, Jul 18, 2022
  4. JohnPrius21

    JohnPrius21 Junior Member

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    No error lights on the dash. Thanks for the suggestions.


    Thanks for the document. Since I’m in California, does that mean I have until 150,000 miles to get this fixed? I’m at almost 80,000 miles now. Debating if I should take it to the dealer right away or not.
     
    #4 JohnPrius21, Jul 18, 2022
  5. Mendel Leisk

    Mendel Leisk Senior Member

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    4th gens have been having an issue with coolant leaks in the exhaust heat recovery system.

    That said, I had more-or-less the same experience with a 3rd gen (purchased new in 2010): coolant levels in both reservoirs gradually dropped, got to low line around 51K kms (around 7 years ago). I purchased a 4 liter of bottle of Toyota Super Long Life Coolant from dealership (around $25 CDN), topped up both reservoirs, and they haven't budged since.

    Wouldn't hurt to try that first. If it continues to drop, then check out the exhaust heat issue.

    This leaves you with a nearly full bottle of coolant, which you can use down the road, either for a DIY coolant change, or bring it back to dealership when getting it done, have them use it.
     
    #5 Mendel Leisk, Jul 18, 2022
  6. RRxing

    RRxing Senior Member

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    I would take it in as soon as possible, just to be on the safe side of the warranty information.
     
    #6 RRxing, Jul 19, 2022
  7. Doug McC

    Doug McC Active Member

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    You state that you have noticed it slowly dropping over the last two years. Have you ever taken it to a dealership or competent mechanic during that time? Every 6 months or 5000 miles those levels should have been checked and topped off if needed. If that service hasn’t been done, I wouldn’t worry about your 150,000 mile warranty; you probably don’t have one anymore. Take it to a dealership!
     
    #7 Doug McC, Jul 19, 2022
  8. JohnPrius21

    JohnPrius21 Junior Member

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    Thanks everyone for their response.

    Quick update. I bought a gallon of premixed coolant from the dealer, $28, and filled each reservoir to the full line. The engine coolant took only about 6 oz to get from where it was to full. I thought it would be more. The interior shape of the engine coolant reservoir is a bit misleading from the outside. The inverter coolant reservoir needed about 2 oz to get from low to full.

    I don’t think it was ever topped off by the dealer. Given that, I think that a few ounces of coolant loss over 5 years/80k miles is within normal range.

    I will monitor closely for any changes. Thanks again for the suggestions.
     
    #8 JohnPrius21, Jul 20, 2022
    Mendel Leisk likes this.
  9. CooCooCaChoo

    CooCooCaChoo Active Member

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    Yeah, its only when it goes to empty overnight does it become a major concern. As for the reservoirs, they look like thermos type bottles: bottle inside a larger bottle.
     
    #9 CooCooCaChoo, Jul 20, 2022
  10. Mukunda

    Mukunda Junior Member

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    my 2016 Prius stopped on highway after giving coolant light and Check Engine light.
    for me Dealer haven't provided any details except saying below codes causing Engine over heat - Engine has to be replaced and pump has to be replaced
    P00B111, P011511, P148F00 AND P319000
     
    #10 Mukunda, Mar 6, 2023
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