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Headgasket failure imminent?

Discussion in 'Prius v Care, Maintenance and Troubleshooting' started by bkman, Jul 5, 2024 at 2:35 PM.

  1. bkman

    bkman Junior Member

    Joined:
    Apr 2, 2012
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    Location:
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    Vehicle:
    2010 Prius
    Model:
    V
    Hi all!

    2010 Prius with 160K miles on it.

    I’ve cleaned the intake manifold and the EGR pipe about two-three weeks ago.

    The EGR valve and the cooler: haven’t touched them yet.

    The car sat for a couple of days while I was waiting for a side glass replacement.

    I’m in Washington state, no cold startup (the lowest reading tonight was 13°C).

    Got a quick rattle this morning and three codes (no check engine light yet):
    P0300
    P0303
    P0304

    Is this what I think it is: the beginning of the head gasket failure?

    No noticeable engine coolant leak yet.
     
    #1 bkman, Jul 5, 2024 at 2:35 PM
  2. ChapmanF

    ChapmanF Senior Member

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    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    A rattle means the engine misfired. There can be lots of reasons for that, so I'd be inclined to back the question up to "why did it misfire", and let the answer take me to the gasket if that's where it takes me.

    Even the members most likely to jump on any reported rattle as a sign of head gasket doom usually seem to agree that cylinders 1 or 2 are where that doom typically starts. Your misfires being in 3 and 4 might offer even more reason to take a deep breath and pursue the incident as misfiring, cause not yet determined.
     
    #2 ChapmanF, Jul 5, 2024 at 3:26 PM
    Brian1954 likes this.
  3. bkman

    bkman Junior Member

    Joined:
    Apr 2, 2012
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    Location:
    Greater Seattle Area, WA
    Vehicle:
    2010 Prius
    Model:
    V
    BTW, I forgot to mention in the initial post that I performed EGR flow test about a month ago. Got close to normal numbers in Techstream (18-19) despite yet-to-be-cleaned intake manifold and EGR pipe.

    The only difference today was that the car sat for 2-3 nights. I usually do lots of short trips.

    I’ve driven 100 miles mostly highway since I wrote this post and haven’t heard a single misfire.

    I will try to do a radiator pressure test sooner than later - but Amazon keeps delaying my order for CTA Tools 7103 adapter- are there any alternatives that I could buy? Already got the Maddox radiator pressure test kit from HF.
     
    #3 bkman, Jul 5, 2024 at 6:12 PM
  4. bkman

    bkman Junior Member

    Joined:
    Apr 2, 2012
    47
    8
    1
    Location:
    Greater Seattle Area, WA
    Vehicle:
    2010 Prius
    Model:
    V
    Well, I have a privilege of owning both 2010 Prius and 2012 Prius v.

    Just did a test with a liquid on 2010 and it doesn’t look good:

    When the same test was performed on 2012 Prius v, the liquid came the same color.

    Probably will do a pressure test just to be sure, but I desperately need an adapter for the tank.
     
    #4 bkman, Jul 6, 2024 at 1:02 PM
  5. Mendel Leisk

    Mendel Leisk Senior Member

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    Location:
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    Vehicle:
    2010 Prius
    Model:
    Touring
    Head gasket failure on 3rd Gen (and v) usually starts with coolant leaking into cylinders. That tester detects carbon monoxide in coolant, which I would speculate happens later, if at all. Try boroscope inspection first thing in the morning, looking for pooling coolant atop pistons.
     
    #5 Mendel Leisk, Jul 6, 2024 at 2:25 PM
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