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2008 Prius is louder when accelerating.

Discussion in 'Gen 2 Prius Technical Discussion' started by Janza, May 8, 2023.

  1. Janza

    Janza Junior Member

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    2008 Prius with 182k miles. Still getting approx 43mpg.
    The other day I thought that my Prius was running louder than normal when accelerating. I googled what one sounds like when a Catalytic converter is stolen, and I don’t think it’s that. It’s more of a low groan….possibly it’s taking longer to shift gears, but not 100% sure. I’m not receiving any warning lights.
    I’ve owned since October 2020. I’ve replaced brakes, serpentine belt, and another thing I can’t remember at the moment.
    I need to take it in for an oil change, don’t know if that’s it, but wondering if anyone else might have ideas. Trying to attach clips of sound.
     
  2. Janza

    Janza Junior Member

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  3. bisco

    bisco cookie crumbler

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    exhaust leak?
     
  4. dolj

    dolj Senior Member

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    My first thought was you have a leak in the exhaust system somewhere. Apart from looking for holes where the pipe has rusted through, check that you have a good seal where the exhaust connects to the manifold.

    As an aside, given what maintenance you've already done, you could easily do your own oil changes. Only takes a ½ hour, one hour tops. The tools required are minimal too.


    [Edit] Just saw your video which wasn't visible when I first posted. From that video I can't really hear any abnormal noise, sorry.
     
    #4 dolj, May 8, 2023
    Last edited: May 8, 2023
  5. PriusCamper

    PriusCamper Senior Member

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    When Hybrid batteries get older and lose capacity the Prius computers will adjust to that loss by relying on the engine more than the pack... This sound of a louder engine will directly correlate to being down to only 1, 2 or 3 bars of remaining charge on your display screen and the engine being quieter when you're fully charged according to the display screen.
     
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  6. edthefox5

    edthefox5 Senior Member

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    Exactly what Camper said.

    43 mpg's is Stage 1 of hybrid battery death and that requires alot more gas pedal to meet your expectations of normal acceleration.

    The engine will complain loudly from this as now it's basically being flogged to meet that expectation. I documented all these stages when my 07 bought new went through its life changes of slow death.

    The death happens so slowly and gradually you don't even notice it till the dreaded RTOD.

    The hybrid battery supply's the bulk of power to this go kart of a car.Without a healthy hybrid battery its truly a go kart of a car.
     
  7. PriusCamper

    PriusCamper Senior Member

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    It's actually just the nature of Nickel-based batteries and with proper deep cycling to restore capacity at least every 18 months in the pack's later years you can extend the lifespan for many, many years. Of course Toyota was hoping you'd forget about basic NiMH knowledge that's been around since early 90's and instead pay them many thousands of dollars to replace your perfectly good pack that needs its capacity restored... :)

    Of course upgrading your pack to Nexcell Lithium improves overall performance so much, there's no need to use a battery chemistry that hasn't been a leader in advancement for more than a 1/4 century.
     
    #7 PriusCamper, May 15, 2023
    Last edited: May 15, 2023
  8. TheLastMojojomo

    TheLastMojojomo Active Member

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    The noise/tone your engine/exhaust is making is definitely indicative of an exhaust leak. It could be that your catalytic converter was stolen or at least an attempt was made to steal it and the exhaust is partially cut... resulting in the noise and tone from your engine in the video.

    Also the Prius doesn't shift gears as it's an eCVT. It only varies output between the Engine and Hybrid Battery to propel the MG2 Gear.

    Posted via the PriusChat mobile app.
     
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  9. Janza

    Janza Junior Member

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    Thanks for your response @PriusCamper . Is there a link somewhere to find out how one would go about this “deep cycling” process?
     
  10. Janza

    Janza Junior Member

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    Thanks everyone. I didn’t realize that I had received responses (must’ve had notifications off). I’m taking it to a mechanic today with all of this info in my back pocket.
     
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  11. PriusCamper

    PriusCamper Senior Member

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    Probably reading hyrbid automotive's website is best explanation of it all, but there equipment quality and cost is miserable... But you can build your own gear here: Build Hybrid Battery Maintenance Gear For Under $100 | PriusChat
     
  12. Janza

    Janza Junior Member

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    Apologies I never updated. Took it to a mechanic who told me the muffler somehow fell off. (Some of these Jersey roads are pretty bad). Anyway, it was replaced and all is good now.
     
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  13. bisco

    bisco cookie crumbler

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    hard to believe it was only a low groan without a muffler
     
  14. PriusCamper

    PriusCamper Senior Member

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    Just like how Eskimos have dozens of words for snow, so too we need dozens of words to define "noisier."

    In my experience the weak point in the exhaust pipe is the sharp bend before the muffler connects... Salty roads seem to do the most damage in that specific spot. Probably wise to put some kind of wrap or cover for that area if you live in salty slushy road land...
     
  15. Brucetafer

    Brucetafer Member

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    if all the engine mounts are toast it will split the exhaust at the header..
     
  16. TMR-JWAP

    TMR-JWAP Senior Member

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    Don't forget, it uses two catalytic converters and a resonator before it even gets to the muffler. Basically (2) 10" mufflers and then another 20" muffler before the pipe even gets to the rear wheels.