Toyota 2016 prius engine problem

Discussion in 'Gen 4 Prius Technical Discussion' started by Ferenc h, Apr 7, 2026 at 6:54 PM.

  1. Ferenc h

    Ferenc h New Member

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    hi everyone, i have a 2016 prius, oil change every 6000 miles. the engine light is flashing. the computer is showing a misfire code, the car shakes when accelerating. my friend says it's a head gasket problem. but the coolant doesn't go away, and the engine oil is fine, there's no water in it. does anyone have any ideas? is it the head gasket? thx everyone it only has 130 thousand miles on it, and i never drove it fast or aggressively we changed the spark plug and it was rusty, but it didn't help
     
  2. bisco

    bisco cookie crumbler

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    coolant level has not gone down at all?
     
  3. Ferenc h

    Ferenc h New Member

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    thanks for the answer, no, the tank is completely full, like always before.
     
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  4. ChapmanF

    ChapmanF Senior Member

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    Head gasket problems have commonly been presenting as engine shakes right away on cold start, then smoothing out after a while.

    Shakes when accelerating (mid-load accelerating, not floored) might indicate the intake manifold EGR passages are (unequally) clogged, because those mid-loads are when EGR happens, not at idle and not when floored.

    Lots of other things also can cause misfiring under various conditions.
     
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  5. BiomedO1

    BiomedO1 Senior Member

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    You need to read the error codes, rather than guessing at the problem or consulting AI. Since you changed the spark plugs. you didn't identify which cylinder was missing and didn't notice any differences in any of the spark plugs?
    You should probably take the car to a professional, since someone that knows what they're doing would've been able to ID the cylinder that was miss firing by the spark plug tip.

    Good Luck...
     
  6. Ferenc h

    Ferenc h New Member

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    Hi , thankyou sir.
    my friend works in a garage. we put a computer on it. show me misfire with the first cylinder. the spark plug was probably wet and rusty. we replaced all four but it didn't help
     
  7. Ferenc h

    Ferenc h New Member

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  8. Mendel Leisk

    Mendel Leisk MMX GEN III

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    ^ And have that mechanic try rearranging the coil and spark plugs, moving them to different cylinders, see if the code changes. For example, if the code was p0302 (misfire on cylinder 2), and you swap coils/plugs between cylinders 2 and 4, IF the code changes to p0304, it's likely those coils/plugs that's the problem.
     
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  9. Ferenc h

    Ferenc h New Member

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    Hi , yes thanks for everybody. Dont have headgasket issue. My problem is IGNITION COIL . So if you have somebody same problem never give up :- D thanks for everybody again have good day
     
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  10. BiomedO1

    BiomedO1 Senior Member

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    That's a really bad picture, but yes - if that was #1 spark plug it looked like it was running rich - not firing. It would've been easy to just move the ignition coils to isolate the REAL issue, than just firing a parts cannon at the car.

    Live and Learn; don't skip troubleshooting steps and details matters since all we have is what you've written here....
     
  11. Ferenc h

    Ferenc h New Member

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    I'm a very beginner and I'm scared. Sorry for everyone