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Prius running rough and misfiring.

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by bootsncatsmeow, Dec 28, 2019.

  1. bootsncatsmeow

    bootsncatsmeow New Member

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    Have a 2010 Prius that is misfiring and running rough. I thought it was the egr cooler, egr valve and the intake manifold. Took it to hybrid 911 to get it cleaned out. Still having the same issue when I go above 40 car starts to misfire. I’ve replaced the spark plugs within the last 10k miles. Not sure if I got a bad one or need to replace the coils. I got the engine compression test while it was at the shop since the mechanics said it was the motor going out however the compressions fine.
     
  2. JC91006

    JC91006 Senior Member

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    I wonder if those guys at hybrid 911 knows how to do a compression test on a Prius.

    But regarding your problem, the symptoms sure sound like a bad head gasket. Since you did a compression test, did you take a good look at the spark plugs while they were out? Maybe switch the coils to see if the misfire jumps to another cylinder? Maybe check if there's coolant in the cylinders?
     
  3. scona

    scona Active Member

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  4. tankyuong

    tankyuong Senior Member

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    When it it gets rough rev up ur engine, but gotta cleanuour egr
     
  5. bootsncats24

    bootsncats24 Junior Member

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    Yeah it ended up being the head gasket. Being quoted 2800 for a used motor with less than 50k and 1900 to do the head gasket.
     
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  6. bisco

    bisco cookie crumbler

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    depends on the motor year i suppose. head gasket might be fine, depending on miles too.
     
  7. bootsncats24

    bootsncats24 Junior Member

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    Probably going to go with a used motor since it is burning oil and reading up on the forums if its burning oil its pointless to do the headgasket. Hybrid 911 has rebuilt motors installed for 2700 but that kind of seems to good to be true.
     
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  8. bisco

    bisco cookie crumbler

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    i have read even better prices, so i think it's only their reputation you need to be concerned about.

    but if they couldn't diagnose a blown head gasket...
     
    #8 bisco, Dec 31, 2019
    Last edited: Dec 31, 2019
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  9. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    +1.

    How much did you give them for the misdiagnosis and failure to correctly repair the problem the FIRST time?

    Would they be willing to subtract that from the $2800 quote?

    Do they offer a warranty for the new/old engine?

    ....$2800 is a reasonable figure for a correctly installed long block but I'd also be interested in figuring out WHY the head gasket let go in the first place and determine if the new/old engine has new/old things like......um......throttle body and intake, EGR cooler, etc.

    Good Luck!
    Updates, please.
     
    #9 ETC(SS), Dec 31, 2019
    Last edited: Dec 31, 2019
  10. Mendel Leisk

    Mendel Leisk Senior Member

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    There's another route, not sure of the pros/cons:

    Get a brand-new short block, which is basically everything below the head gasket. Maybe not the oil pan, not sure about that. Also would not include water pump, oil filter assembly, stuff like that, which is readily transferred over. These are around $1700 in the States, cash-and-carry?

    Then have a machine shop rebuild the head, maybe around $500.

    Then have your mechanic reassemble everything with a complete gasket kit (including head gasket, Toyota gasket kit's around $175~200).

    This thread has a lot of relevant info. It's not really the above described process, but similar:

    2011 Prius Head Gasket Failure | PriusChat

    Or..., a low miles 4th gen engine. There's a thread here on that. It reuses the third gen intake and exhaust manifolds, and EGR system. Also there's two components at the transaxle interface that need to be swapped for 3rd gen. There's a thread here on that if you're interested:

    Swapping in a Gen 4 Prius' 2ZR Engine into the Prius v | PriusChat

    Note the swap is into a Prius v, but the principal is the same.

    Then, there's a guy here who transferred over the 4th gen EGR as well (assuming your salvage engine comes with it): this required modding the 3rd gen exhaust manifold, heating/bending the pipe connecting to the EGR, to align EGR with 3rd gen intake manifold. I believe he posted info in the aforementioned thread.

    Short block and overhaul gasket kit are both shown on this page:

    Engine for 2015 Toyota Prius | Toyota Parts

    Note, I would spec a 2015 short block, hopefully ensures you get the revised pistons and rings.
     
    #10 Mendel Leisk, Dec 31, 2019
    Last edited: Dec 31, 2019
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  11. bootsncats24

    bootsncats24 Junior Member

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    one year warranty 12k miles. I had them clean out the egr system and the intake manifold. I originally thought those were clogged and were causing a misfire since when I unplug the egr the car ran fine. Has them clean it out car was still misfiring so I had them compression test it then took it to another shop.