Safe to have inverter coolant slightly overfilled?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by ericspoor, Apr 27, 2019.

  1. ericspoor

    ericspoor Member

    Joined:
    Jul 25, 2018
    76
    36
    0
    Location:
    austin
    Vehicle:
    2005 Prius
    Model:
    Base
    I noticed my inverter coolant was about 3mm below the low line so i topped it off with oem coolant. Now it is a little less than 1 centimeter above the full line. Will this cause issues? Thanks for your expertise!
     
  2. bobodaclown

    bobodaclown Member

    Joined:
    Feb 22, 2012
    214
    71
    0
    Location:
    USA
    Vehicle:
    2009 Prius
    Model:
    Base
    You're good to go.
     
    Raytheeagle likes this.
  3. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    10,264
    12,601
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    It doesn’t have to be precise. The tank is there to provide room for thermal expansion and reserve supply for thermal contraction. Just keep it close to the line and get it checked if it starts to get lower.
     
  4. DThrill

    DThrill Junior Member

    Joined:
    Jun 3, 2018
    8
    7
    0
    Location:
    Phoenix, AZ
    Vehicle:
    2010 Prius
    Model:
    II
    If inverter fluid levels drops suddenly and it is a large quantity, you may have a head gasket leaking fluid into the heads. Please have your car checked ASAP or if you start noticing hard starts/knocks, engine coils misfiring!! I waited to have mine checked and had to have a partial engine rebuilt. :(

    when the techs plugged in computer diagnostic, all they got was misfiring engine coils. we changed out all the spark plugs,wires and engine coils-- but I forgot to tell them about the inverter fluid drop cause I had refilled it. 1 week later, engine light comes on and some rough starts and misfirings start over again-- I was going to drop it off at shop after work, but it was too late, Overheat light came on..I turned off car right away and coasted my way into a parking spot. Inverter coolant was ALL gone! I refilled and slowly drove it to shop where I got the bad news.

    Lesson learned the hard way.
     
  5. davecook89t

    davecook89t Senior Member

    Joined:
    May 10, 2016
    1,036
    759
    0
    Location:
    Washington State, Florida
    Vehicle:
    2017 Prius
    Model:
    Four Touring
    Inverter and ICE cooling systems are totally separate. Inverter coolant cannot leak into the cylinders. If the coolant in the ICE radiator drops suddenly, on the other hand, that could indicate a leaking head gasket.
     
    jerrymildred likes this.
  6. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    10,264
    12,601
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    @davecook89t is absolutely right. Inverter and ICE coolant are not connected. The inverter coolant cools the inverter, not the engine.

    If the inverter coolant level is falling, it's simply leaking. Most likely a hose connection.
     
Loading...