Gen 3 Prius Owners (2010–2015) – Important Action on Head Gasket & Hybrid System Failures

Discussion in 'Gen 3 Prius Main Forum' started by caprib, Jan 12, 2026 at 2:55 PM.

  1. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    114,261
    52,096
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    it's one thing to replace inverters, and a whole nuther to replace engines. the inverter lawsuit was about safety
     
    BiomedO1 likes this.
  2. BiomedO1

    BiomedO1 Senior Member

    Joined:
    Mar 27, 2021
    3,795
    1,975
    0
    Location:
    SacTown, Ca
    Vehicle:
    2021 Prius Prime
    Model:
    LE
    The court also ruled that Toyota must fix it, even if it's a salvaged car. In other words, If someone puts together a FrankenPrius - Toyota must fix that inverter too as long as the VIN meets the inverter suit parameters..........
     
  3. Mendel Leisk

    Mendel Leisk MMX GEN III

    Joined:
    Oct 17, 2010
    60,499
    41,646
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    There is a somewhat astounding statement in my North American 2010 Prius Owner’s Manual:

    IMG_2953.jpeg

    I also got this letter from Toyota Canada:

    IMG_2944.jpeg
     
    #23 Mendel Leisk, Jan 14, 2026 at 7:22 AM
    Last edited: Jan 14, 2026 at 7:33 AM
    BiomedO1 likes this.
  4. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    27,730
    18,318
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    The letter makes another appearance with a red circle around "While the majority of vehicles will not experience this condition", but no red circle around what condition the letter was about.

    The condition that particular letter was about is (just above the red circle that's there) "a sticking EGR valve due to excess carbon build-up" when that condition causes cold start-up misfiring.

    I don't actually know how many vehicles ever do experience that condition. There are occasional posts here where people have found their EGR valve stuck with carbon build-up, but it doesn't seem like a lot of them.

    Other conditions, like rutted ski jumps and clogged coolers, may be encountered more often. (And, of course, a notorious condition that can cause cold start-up misfiring is a damaged head gasket, whatever may have caused that.)
     
    BiomedO1 likes this.
  5. BiomedO1

    BiomedO1 Senior Member

    Joined:
    Mar 27, 2021
    3,795
    1,975
    0
    Location:
    SacTown, Ca
    Vehicle:
    2021 Prius Prime
    Model:
    LE
    Sorry should've of been clearer on my post; 300K miles not KM

    That quart for every 600 miles oil burn seems to be industry standard. I believe Subaru also uses that standard to determine engine replacement. Mind you that this consumption would empty your oil sump in less than 2500 miles - for those that don't check their oil levels be it 5K or 10K mile oil change intervals......
     
  6. BiomedO1

    BiomedO1 Senior Member

    Joined:
    Mar 27, 2021
    3,795
    1,975
    0
    Location:
    SacTown, Ca
    Vehicle:
    2021 Prius Prime
    Model:
    LE
    There was a guy from the UK that had 200K+ miles on the clock on a very early gen4. Only did oil changes but didn't do coolant change. His EGR valve locked-up and had a slight hesitation on acceleration. The EGR error code was there the entire time he was parts swapping.o_O
    He did plugs, coils, throttle body clean-out x2; before jumping on to the forum to ask us.
    He posted pictures afterwards and the jammed valve looked more corrosion than carbon fouled.
     
    #26 BiomedO1, Jan 14, 2026 at 11:27 AM
    Last edited: Jan 14, 2026 at 11:45 AM