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Is this engine low compression? I know it might Engine

Discussion in 'Gen 2 Prius Main Forum' started by Retsukowind, Dec 11, 2021.

  1. Retsukowind

    Retsukowind Junior Member

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    I have a 2006 Toyota Prius with 208,171 miles and the engine shakes on low idle continuously when I start it up and when the battery gets low and engine kicks on it's misfires and shakes quite a bit. Also there is oil in the air intake and gas smell strong in the air intake. Also burns oil a little, but I feel that the compression might be low and oil jumping in the cylinder might cause it. I just want a sound opinion on the engine symptoms, I replaced the spark plugs, spark plug coils, timing chain system, and O2 sensors.
     
    #1 Retsukowind, Dec 11, 2021
  2. Retsukowind

    Retsukowind Junior Member

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    #2 Retsukowind, Dec 11, 2021
  3. SFO

    SFO Senior Member

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    Do you have any warning lights being displayed on the dash, or OBD2 codes worth posting?

    How long have these symptoms being going on?
    Did you have a reported OBD2 code that necessitated throwing parts at the problem, and did the replacements make a difference?
    Knockoff parts are a thing now, were those parts replaced from a local retailer/dealer, or from online purchases?

    Which spark plugs; brand/part# did you use?

    What did the old plugs look like?

    Did the old coils (COPS) have any carbon tracking?
    What did you actually replace?
    Did you use Toyota OEM or Denso replacements, or some other aftermarket?
    Have you ever used a PEA additive in the gas tank?

    Won't take long to clean up the MAF sensor and butterfly valve, then disconnect the 12v for a few minutes to reset the fuel trims. Might help.
     
    #3 SFO, Dec 11, 2021
    Last edited: Dec 11, 2021
    Raytheeagle, PriusCamper and edthefox5 like this.
  4. edthefox5

    edthefox5 Senior Member

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    I'm with SFO where did you buy the plugs & coils? If anyplace other than dealer online you probably have counterfeit plugs and coils. Especially coils.

    If she's misfiring she's throwing codes and possibly other codes to tell you wjy its unhappy. What are the codes?

    And most importantly has the engine oil ever gotten so low it turned on the check engine light and it was blinking?
     
    #4 edthefox5, Dec 11, 2021
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  5. Retsukowind

    Retsukowind Junior Member

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    They are ngk ruthenium and the coils are aftermarket but shaking still happened before it was replaced, o2 sensors are Denso from Toyota, I never let the oil get low but the previous owner might have. Oil in the air intake though. I cleaned the MAF and butterfly, also disconnected the 12v, also used an aftermarket timing chain system since the vvti gear on the old one went bad and the spring failed in it but the timing is not the issue. Also replaced the fuel injectors before. Only 1 code for misfire.
     
    #5 Retsukowind, Dec 12, 2021
  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah dang it, do you mean you replaced the timing chain? I think so, but this "system" expression is confusing.
     
    #6 Mendel Leisk, Dec 12, 2021
  7. edthefox5

    edthefox5 Senior Member

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    May be time for a compression check the engine may just be whooped. i would have done that before the time chain replacement that's a very big job.

    And the aftermarket coils are bad news but I understand as the real coils are $105 each. Ya get what you pay for.

    Compression check next.
     
    #7 edthefox5, Dec 12, 2021
  8. Retsukowind

    Retsukowind Junior Member

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    Will do a compression test next then, thanks for the help, I'm still daily driving it btw, with refurb hybrid battery only being replaced a while back ,I only get 41.9 mpg I lose 10mpg but I can live with that for a while. Timing on the engine was very easy, mostly used power rachet for everything.
     
    #8 Retsukowind, Dec 13, 2021
    Last edited: Dec 13, 2021
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