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Misfire without throwing a code?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by TommieG, Feb 7, 2019.

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  1. TommieG

    TommieG Junior Member

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    First of all, thanks to all of you that have "cut your teeth" on the Prius and have been kind enough to share your knowledge with the rest of us!
    I have recently purchased a 2007 232K miles with good maintenance history.
    Here's what I was told:
    • The 12V and traction batteries recentIy changed
    • Fresh oil change (overfilled, but not corrected yet)
    • It had the knocking noise at all speeds that so many have said was a misfire.
    Here's what I have done.
    • I cleared all codes, however before I did I think the only one that seemed related was something like "poor engine power".
    • Changed injectors, cleaned MAF, replaced very oil-fowled plugs, changed coil packs
    I started it last night after changing the coil packs and it is still making the noise. I didn't let it run very long as I was so afraid of what the next step might be. So, as a consequence I did not see any lights before shutting it down. Is it still possible that I could have a misfire without a code? Could the high oil level be causing this? Is the engine toast? Please haelp.......

    Thanks in advance,
    Sleepless In Alabama
     
    #1 TommieG, Feb 7, 2019
  2. bisco

    bisco cookie crumbler

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    are you reading the codes with toyota tech stream?
     
    #2 bisco, Feb 7, 2019
  3. padroo

    padroo Senior Member

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    You need to do a compression test or a cylinder leak down test to see if the engine is capable of making power.
    Looks like you covered most all the other causes except low fuel pressure.
     
    #3 padroo, Feb 7, 2019
  4. TommieG

    TommieG Junior Member

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    No, I'm using a BlueDriver. Very good diagnostic device.
     
    #4 TommieG, Feb 7, 2019
  5. TommieG

    TommieG Junior Member

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    Is there any kind of reset that I should do since all these parts were replaced?
     
    #5 TommieG, Feb 7, 2019
  6. TommieG

    TommieG Junior Member

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    I just thought about something else. "Supposedly " the problem with the ICE started after the batteries were replaced.
     
    #6 TommieG, Feb 7, 2019
  7. Skibob

    Skibob Senior Member

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    You are the 3rd person lately to have that code.
     
    #7 Skibob, Feb 7, 2019
  8. TommieG

    TommieG Junior Member

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    Here's a video of the engine making the noise. This is from a cold start after settling down.

     
    #8 TommieG, Feb 7, 2019
  9. TommieG

    TommieG Junior Member

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    I have a new wrinkle in the mystery, I drained the excess oil, which was almost a quart. Started the engine with no smoke abd the same knocking noise. After only running a short while, I pulled out the new plugs just to take a look, All of them had oil in them. (I guess I should have thought something was odd whenever I saw the original plugs were all oil fouled.) I looked inside the sparkplug holes and did not see any oil, so head or rings or what??
     
    #9 TommieG, Feb 11, 2019
    Last edited: Feb 11, 2019
  10. edthefox5

    edthefox5 Senior Member

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    Blown motor for sure. Main bearing or piston wrist pin failure very common. Start looking around for used motor.

    Motor replacement very common on this site. Usually caused by running the engine out of engine oil.
    So many people have destroyed there motor on this site because they can’t be bothered checking the oil
    As many high mileage g2 motors eat oil.

    And your hybrid battery wasn’t replaced it was repaired using the same used vintage age battery’s so it probably wont run long before it fails again so sorry for the double bad news.

    Becoming a common story on here,
     
    #10 edthefox5, Feb 11, 2019
  11. TommieG

    TommieG Junior Member

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    I'm not doubting what you say, but am trying to learn and understand. How would the lower end problems cause oil fouled plugs?
     
    #11 TommieG, Feb 11, 2019
  12. Patrick Wong

    Patrick Wong DIY Enthusiast

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    The failed bearing is indicative of poor engine lubrication. That lack of lubrication may also have resulted in worn pistons and/or cylinder bores, thus allowing excessive oil to get past the piston rings into the combustion chamber.

    In any event you need to replace the engine if you plan to keep the car. I suggest you have a local trusted mechanic verify that the engine is dead (identify the source of the knock, take a compression test, etc.), then decide what you are going to do about it.
     
    #12 Patrick Wong, Feb 12, 2019
    Raytheeagle likes this.
  13. TommieG

    TommieG Junior Member

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    What you are saying makes sense.,,,,,,,I knew I cane here for some reason. Thank you, thank you!
     
    #13 TommieG, Feb 12, 2019
  14. jleeds

    jleeds New Member

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    Sorry to revive this, but was a worn bearing the cause of the sound? My Gen 2 recently started to make this sound and am looking for alternatives other than the default "your engine is on its way out". I haven't yet pulled the plugs (tonight) but will be doing that. Also, when I watch the monitors for VVT on my scanner I show that the ecu isn't making any adjustments to the timing. Is that also a symptom?
     
    #14 jleeds, Mar 12, 2021
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