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

Engine and inverter coolant

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Functional, May 12, 2022.

  1. Functional

    Functional Junior Member

    Joined:
    Jul 14, 2017
    20
    2
    0
    Location:
    California
    Vehicle:
    2009 Prius
    Model:
    ----USA----
    Hello.
    I have a 2015 Prius with 68k miles. I am the second owner.

    The engine and inverter coolant are close to the low mark. I don’t suspect any leakage.

    Engine coolant and Inverter coolant replacement is suggested at 100k/10 years.

    Best way to check for leaks?
    And if there are no leaks, should I just top off? Or do the replacement and fill early?

    Thanks
     
    #1 Functional, May 12, 2022
  2. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,738
    38,260
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Just top up. Ours was at the low lines (both), around 5 years in, happened very gradually. Topped them up and they stayed there, till I did a change at 10 years.
     
    #2 Mendel Leisk, May 12, 2022
  3. Functional

    Functional Junior Member

    Joined:
    Jul 14, 2017
    20
    2
    0
    Location:
    California
    Vehicle:
    2009 Prius
    Model:
    ----USA----
    I just performed a top off.

    just realized that I didn’t need to add much on the inverter and engine coolant…. Used about half a quart…

    was this a waste of a new gallon of coolant?
     
    #3 Functional, May 12, 2022
    Last edited: May 13, 2022
    Mendel Leisk likes this.
  4. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,738
    38,260
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Hang onto it till the 10 year or 100k mile engine coolant change and it’s not.
     
    #4 Mendel Leisk, May 13, 2022
  5. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    11,491
    14,100
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius
    Model:
    Two
    Look for pink spots or runs. The coolant dries pink. But, as others said, it might not be leaking. Some cars have a little of it disappear.
     
    #5 jerrymildred, May 14, 2022
  6. Georgina Rudkus

    Georgina Rudkus Senior Member

    Joined:
    Sep 15, 2018
    3,125
    2,182
    0
    Location:
    Taylors, SC
    Vehicle:
    2012 Prius v wagon
    Model:
    Two
    I'd just change the coolant. The quality of the coolant affects the head gasket and many othe components that it contacts. You don't know how the car was used and driven. Coolant is cheap compared to a head gasket replacement. Worn out coolant can degrade the head head gasket. 10 years or 100k miles is too long.
     
    #6 Georgina Rudkus, May 14, 2022
    Foxglove and nicoj36 like this.
  7. nicoj36

    nicoj36 Active Member

    Joined:
    Oct 15, 2013
    495
    156
    0
    Vehicle:
    2010 Prius
    Model:
    II
    Just drain the old fluid out and replace with new.
     
    #7 nicoj36, May 15, 2022
  8. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,738
    38,260
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    OP’s coolant levels dropped maybe 20 mm’s in the reservoirs, over maybe 7 years of ownership, he’s topped them up, and now he should replace both? When Toyota USA says 10 years or 100k miles (for engine coolant) and 15 years or 150k miles (for inverter coolant)?
     
    #8 Mendel Leisk, May 15, 2022
  9. Georgina Rudkus

    Georgina Rudkus Senior Member

    Joined:
    Sep 15, 2018
    3,125
    2,182
    0
    Location:
    Taylors, SC
    Vehicle:
    2012 Prius v wagon
    Model:
    Two
    I just came home from my local Walmart.

    Red Asian coolant is chreap right now at WalMart. It is Toyota SLCC equivalent. $9.97 for Peak on clearance. $10,97 for Super Tech store brand.

    It better to be absolutely safe for at least the next 5 years.
     
    #9 Georgina Rudkus, May 15, 2022
(You must log in or sign up to post here.)