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Head gasket?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by bshef, Oct 28, 2018.

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  1. bshef

    bshef Active Member

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    engine shake/rattle at start up along with using oil and now noticing low coolant.
    190k... 2005....New toyota Hybrid pack changed out at 155k.
    Appears misfire is coming from first 2 cylinders (looking from left to right)....
    throwing codes 300, 301, 302.
    So - as first step... changed fouled plugs and ran some seafoam through oil and also poured into the gas system hoping this may clear out anything possibly causing sticky lifters.
    Now that's all done and fresh oil changed ......it's still shaking and throwing same misfire codes at start up.
    So....I'm thinking head gasket or just swapping out the engine altogether with one those used japanese engines....
    Has anyone been thru this?....Thoughts/suggestions?
    Thanks
     
    #1 bshef, Oct 28, 2018
    Last edited: Oct 28, 2018
  2. SFO

    SFO Senior Member

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    Did you run the engine low on oil?

    How are you checking the coolant level(s)?

    Are you using techstream for OBD2 reading?

    Did you check the plugs and coils for evidence of carbon tracking or a wet oily condition?

    How did the two (2) misfiring plugs look compared to the others?

    When you changed the oil, did it look like it had coolant in it?

    Have you performed a compression test to determine a faulty head gasket?

    Since you've installed new plugs, you could try swapping the misfiring coils with known good coils (3,4) and see if the misfires follow.
     
    #2 SFO, Oct 28, 2018
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  3. bshef

    bshef Active Member

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    yes.... have run low on oil
    checking coolant by simply looking..
    friend has $40 reader
    I did not check for coolant in the oil... however I just changed the oil yesterday so that is still available to look at its just in the oil tub.
    we talked about swapping the coils but did not do that....
    have not yet done and compression check/test... but plan on Taking it in to mechanic tomorrow....

    SM-G965U ?
     
    #3 bshef, Oct 28, 2018
  4. SFO

    SFO Senior Member

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    Look at the used oil again, does it have a milky appearance? If not the head gasket is most likely fine.

    If the mechanic chooses to check the compression she can also swap the coils around after inspecting them for carbon tracking.
    Be sure to look in the plug holes, as I've seen engine oil pool in #1 before.

    Here is the work up for your reported DTCs, techstream might make it easier to diagnose.

    https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/Prius%20Service%20Manuals%202004/%E4%BF%AE%E7%90%86%E6%89%8B%E5%86%8C/04pruisr/05/2054m/cip0300.pdf
     
    #4 SFO, Oct 28, 2018
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  5. bshef

    bshef Active Member

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    ok.....Appreciate the heads up.
    Thanks for the suggestions - will definitely pass this info along to the mechanic.
    Yes....if I remember correctly....#1 plug did appear a lil wet.
     
    #5 bshef, Oct 28, 2018
  6. Dxta

    Dxta Senior Member

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    Don't conclude its a gasket problem yet. A lot of things can cause such codes to set, ranging from ignition, mechanical, to fuel relates issues.
    Check the injectors if they are clogged with carbon deposits.
     
    #6 Dxta, Oct 29, 2018
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  7. 05PreeUs

    05PreeUs Senior Member

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    Unless the engine overheated or someone ran a witch's brew of coolant in it, a failed HG is about the LEAST probable cause.

    As others have suggested, a coil issue is FAR more likely and if it ran low on oil, the rod bearings may have been damaged. In any event, a LEAK DOWN test, NOT a compression test, will tell everyone if the cylinders/valves are serviceable.
     
    #7 05PreeUs, Oct 29, 2018
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  8. bshef

    bshef Active Member

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    Well, thx for those suggestions....gives me lil more hope than what I was thinking yesterday.
    I'm gonna pick up couple new coils today and swing by toyota for some the coolant.
    We have a local mechanic that I'll talk to today see what he thinks!
    I'll check back in here with an update!
    Thank fellas
     
    #8 bshef, Oct 29, 2018
  9. Mendel Leisk

    Mendel Leisk Senior Member

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    I'm skeptical it's not the head gasket: what with the coolant consumption, and the codes you're getting.
     
    #9 Mendel Leisk, Oct 29, 2018
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  10. bshef

    bshef Active Member

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    oil was coffee black.....(had just run seafoam thru it)..... nothing milky looking to it....
     
    #10 bshef, Oct 29, 2018
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  11. Mendel Leisk

    Mendel Leisk Senior Member

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    Any pink, crusty stuff under the water pump?
     
    #11 Mendel Leisk, Oct 29, 2018
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  12. bshef

    bshef Active Member

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    Hey Mendel.....good suggestions..lemme go check here after breakfast....(I did new water pump about 3 yrs ago).
     
    #12 bshef, Oct 29, 2018
  13. SFO

    SFO Senior Member

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    in the radiator, and not just the overflow tank/reservoir?
     
    #13 SFO, Oct 29, 2018
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  14. Mendel Leisk

    Mendel Leisk Senior Member

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    Was gonna put a like on that, then remembered: OP's problem is with a 3rd gen, which has no radiator cap. I can recall with humour looking for it...
     
    #14 Mendel Leisk, Oct 29, 2018
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  15. bshef

    bshef Active Member

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    FYI...Mine's gen 2.....2005
    and yes......I just topped-off the coolant in the reserve tank....then ran the engine with the heater on for spell......level didn't budge.
    I'll go back out now and pull the radiator cap and check the level there also....
     
    #15 bshef, Oct 29, 2018
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  16. bshef

    bshef Active Member

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    rut-roh.....
    went out to install 2 new coils tonight and the brand new plug just installed last week cylinder 1 is already oily and fouled. :(
    I'm back to thinking I need new engine or possibly just time to upgrade the car now after 14 years.
    This thing does have a new hybrid battery from toyota with only 40k miles on it....so I guess it's probably worth a little.
     
    #16 bshef, Oct 29, 2018
  17. JC91006

    JC91006 Senior Member

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    Maybe you just need a valve cover gasket
     
    #17 JC91006, Oct 29, 2018
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  18. bshef

    bshef Active Member

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    really?....but the oil's showing up in the cylinder on the bottom of the plug.....!
    Seems to me a valve cover gasket would just show oil on the outside and maybe just around the plug boot.
     
    #18 bshef, Oct 29, 2018
  19. 05PreeUs

    05PreeUs Senior Member

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    Wait, you pulled the plug(s) out before/during coil replacement?
     
    #19 05PreeUs, Oct 29, 2018
  20. Mendel Leisk

    Mendel Leisk Senior Member

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    Maybe not every time, but seems like a lot of stories here involved ignition coils being replaced, that doesn't help, down the road it's engine rebuild or swap time. Who knows, but it seems like the odds are long: betting on coils being the problem.
     
    #20 Mendel Leisk, Oct 29, 2018
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