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Prius shuddering on slow acceleration

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by RudeBoiM3, Aug 19, 2015.

  1. RudeBoiM3

    RudeBoiM3 Do it once, Do it Right!

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    Hi guys! I have a 2010 Prius Pkg 5 with around 71xxx miles. I usually drive it like a regular car on eco mode and get around 38mpg average but recently I've changed my style of driving where I accelerate to the desired speed limit, let go of the gas, then reapply and keep the mpg meter in between the middle eco line and before the pwr band. I'v been able to average 44mpg this way, which is great! However, what I've begin to notice now is that say if I'm traveling at say around 45mph and let go of the gas and re-apply, the engine starts to shudder as if it's not getting enough gas. Anyone know why this is happening? I also need new tires (215/45/17) but that doesn't have anything to do with this. I've owned this car since 30xxx miles and haven't done anything other than put gas and change the oil at the dealerships. Could putting 87 octane gas with up to10% ethanol have any effect on this? Just looking at my options now. Thanks for the help!
     
    #1 RudeBoiM3, Aug 19, 2015
  2. mmmodem

    mmmodem Senior Taste Tester

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    Between 42 - 46 mph is when the ICE goes on and off if you stay below midline on the HSI. There is a slight shudder when this happens.

    If you let go of the gas at 45 mph and slow to 42 mph, the ICE shuts off. If you press on the gas again above midline, ICE comes on shuddering and there will be a momentary lag before you get any useable power.
     
    #2 mmmodem, Aug 19, 2015
  3. RudeBoiM3

    RudeBoiM3 Do it once, Do it Right!

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    I've noticed the shuddering at higher speeds as well. It starting to get annoying as it makes me feel like the engine is about to give up on me at any time.
    I also forgot to mention that I've had to put oil in the car around every 4k miles because it seems to have burned it up. There are no visible leaks anywhere. I assumed it's normal from aggressive acceleration.
    Can I do something to improve the performance of the engine? Does Seafoam or STP work well with Prius?
     
    #3 RudeBoiM3, Aug 19, 2015
  4. JC91006

    JC91006 Senior Member

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    How much oil do you add at 4k miles? You should do a throttle body and throttle plate cleaning to see if it improves your shuddering condition.

    Also if you haven't changed your air filter before, it's a good time to do it too
     
    #4 JC91006, Aug 19, 2015
    Last edited: Aug 19, 2015
  5. alekska

    alekska Active Member

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    And clean/check EGR pipe and valve, too

    - Alex
     
    #5 alekska, Aug 19, 2015
  6. RudeBoiM3

    RudeBoiM3 Do it once, Do it Right!

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    As I said, outside of basic oil changes from the dealership, I haven't done anything else on the car. The last time I burnt thru oil I added over a quart.
     
    #6 RudeBoiM3, Aug 19, 2015
  7. JC91006

    JC91006 Senior Member

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    As long as you don't let your oil level drop below the bottom (low oil) mark on the dipstick, you should be fine. Maybe you should change your transaxle fluid as well, while you're doing a little maintenance.
     
    #7 JC91006, Aug 19, 2015
  8. olibiloli

    olibiloli Junior Member

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    I have a Prius 2010 with 52K, first owner, having the same problem. It goes away if I'm accelerating fast (that what I'm doing now, gives me a better mileage too :), kinda "sporty" driving. New spark plugs, ignition coils, intake manifold, ATF, but it didn't get any better. I think the EGR system needs to be cleaned, it's gonna be my next big project :) The car runs great otherwise, slow acceleration is a killer.
     
    #8 olibiloli, Aug 19, 2015
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  9. qdllc

    qdllc Senior Member

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    How often do you run a high-strength fuel system cleaner? Something like B-12 Chemtool or Seafoam? I do it at least every 10,000 miles. Little things build up in FI systems, and this has been so since the day they first came out. A good fuel system cleaner/solvent solves a lot of problems.

    That would be my first thought. Cleaners like the ones I've named will also clean junk off the spark plugs (even though they are supposed to be self-cleaning) which helps produce cleaner and stronger combustion cycles.
     
    #9 qdllc, Aug 20, 2015
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  10. RudeBoiM3

    RudeBoiM3 Do it once, Do it Right!

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    Good thing you brought up, Seafoam. I have never tried it on the Prius, but have done it on other non hybrid cars and the results have been great. I can definitely feel an improvement on the performance. Question is, how safe is it to do it on the Prius? Can I just empty a full bottle in to the gas tank?
    I got new Michelin Primacy MXM4 tires on last week, and next on my list is replace air filter, throttle body cleaning and seafoam. Thanks for all the advise!
     
    #10 RudeBoiM3, Sep 15, 2015
  11. qdllc

    qdllc Senior Member

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    Perfectly safe.

    The same product comes in 1 gallon cans to submerge parts in to soak. Totally safe to the parts you're cleaning...unless you want to preserve the gum and varnish.

    I have a 6 gallon motorcycle tank, and if I'm in doubt about a fuel system problem, I put a whole can into that with no problems. Normally I just 1/3 of a can. Regular vehicles with more than 10 gallons in the tank will have no issue taking the whole can.

    Just get one of those funnels so you can pour it past the safety blocks at the gas cap.
     
    #11 qdllc, Sep 16, 2015
  12. RudeBoiM3

    RudeBoiM3 Do it once, Do it Right!

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    Ordered oem Toyota filter with suggested cabin air filter from Amazon today. Excited to get my hands dirty and clean this baby up! YouTube has great simple quick videos. Will keep you guys updated with the performance after this maintenance. Any idea if k&n filters or any other after market filters perform better?
     
    #12 RudeBoiM3, Sep 16, 2015
  13. qdllc

    qdllc Senior Member

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    K&N gives better airflow and "reusability" since you can clean and re-oil them with the K&N kit, but the only point for that is to get more HP. On a hybrid, it's a waste. Also, it lets more dirt through because more airflow = less filtration. I don't think it does any long-term harm, but there is a trade off.
     
    #13 qdllc, Sep 17, 2015
  14. RudeBoiM3

    RudeBoiM3 Do it once, Do it Right!

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    update for you guys: so after getting new tires, replacing the main air filter and the cabin air filter, doing a throttle body and mass air flow sensor cleaning, and putting a few cans of seafoam and gumout on gas fill ups, i am happy to say that the acceleration has drastically improved! i am no longer getting hesitation while accelerating! i highly recommend everyone to do this on their car. its easy, cheap and very effective. the prius feels like it's driving better than it did when i bought it with 40k miles. i'm still keeping my eye open on the oil burn and will check again in a 1000 miles but so far i don't smell any burn and the mileage has gone up from avg 38mpg to around 42mpg. thanks everyone for the help!
     
    #14 RudeBoiM3, Oct 21, 2015
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