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Q re: "jerky" shutoff of gas engine

Discussion in 'Gen 2 Prius Main Forum' started by lovebug, Feb 12, 2008.

  1. lovebug

    lovebug New Member

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    Hello, Prius friends!

    Am getting ready to take in car for free oil/filter change & tire rotation
    at 5K miles. I was thinking of just doing myself but wanted dealer to
    look at an issue.

    Sometimes, when stopping at a redlight & the gasoline engine shuts off,
    it does so with a jerk or thumpy feeling. The first time it happened, I
    actually thought someone had bumped me lightly in the rear, but not.
    This does not always or often happen & I am trying to see a pattern, but
    don't. It seems to me in the past the car had always shut on/off silkly smooth that you wouldn't even know you had a hybrid.Of course, when I made appt., the dealer said come in & show the
    tech. what you're talking about. We all know it won't happen then. :)

    Has anyone else expereinced this? Is it normal? Am I nuts?

    Thanks!
     
    #1 lovebug, Feb 12, 2008
  2. qbee42

    qbee42 My other car is a boat

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    This is completely normal. We see this posted as a question more than anything else. What happens is that the Prius engine is always stopped in a particular position that favors restarting with minimum emissions. If the computer misses on the first try, it runs the engine around and tries again. An extra try or two makes the engine shudder when it shuts down. You will see this happen more often with new engines and during cold weather.

    Tom
     
    #2 qbee42, Feb 12, 2008
  3. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
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    Yep. Tom's right.

    Sometimes the engine runs so quietly that you can't tell it's on. Much of the time, it shuts off so smoothly that it's difficult to tell that it's stopped. But every once and a while you get that jerky stop.

    Quite frankly, I would rather take notice of the infrequent jerky stops because it means that it's not the norm. Just think how different it would be if people posted that the shut-off was occasionally uncharacteristically smooth.
     
    #3 TonyPSchaefer, Feb 12, 2008
  4. patsparks

    patsparks An Aussie perspective

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    That jerky stop is telling you the HSD has just entered its most efficient operating mode.
     
    #4 patsparks, Feb 12, 2008
  5. HardCase

    HardCase SilverPineMica, the green one

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    As the others have said, it's normal. First time it happened to me I was stopped at a light and a big yellow Hummer pulled up very close behind me just as the ICE shut down, causing the shuddering sensation you've experienced. Initially I thought the Hummer had nudged my bumper, but when I got to my destination and checked there was no sign of damage.
     
    #5 HardCase, Feb 12, 2008
  6. Jack66

    Jack66 Kinda Jovial Member

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    This is the best explanation I have seen. Thanks! Is there more where that came from in the technical threads that I didn't see?
     
    #6 Jack66, Feb 12, 2008
  7. qbee42

    qbee42 My other car is a boat

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    Yes, there is a wealth of technical information floating about in the forum. Some of it is from me, which makes it suspect, the rest is from reliable sources.

    Tom
     
    #7 qbee42, Feb 12, 2008
  8. perryma

    perryma New Member

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    At first I thought you had cut and pasted my post! Yes I have the same thing going on with mine and it seems it is normal and maybe worse in cold weather. You will get used to it . I just consider it a smack on the behind from the environment saying ,"Hey good choice."
     
    #8 perryma, Feb 12, 2008
  9. ksstathead

    ksstathead Active Member

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    #9 ksstathead, Feb 12, 2008
  10. lovebug

    lovebug New Member

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    Wow, thank you, all my Prius friends who answered!

    I was thinking it happened more when really cold out, but now I understand better and will not worry.

    Again, thanks so much!!!!!

    p.s. my husband asked to borrow my Prius to make a trip to Florida because his RAV-4 v6 gets about 20 mpg, and he figures he will save
    about $180 on the 2K mile round trip. Now I know the car is safe for a
    trip.
     
    #10 lovebug, Feb 12, 2008
  11. ksstathead

    ksstathead Active Member

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    Make sure hubby bones up on P&G, SHM(super highway mode), Warp Stealth, Warp Neutral, etc. Not only will he save $, but it mitigates the frustration of the inevitable traffic delays. His worst mileage will come on the open freeway sections (unless he drives a bit slower than traffic).
     
    #11 ksstathead, Feb 12, 2008
  12. TonyPSchaefer

    TonyPSchaefer Your Friendly Moderator
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    My wife and I can fly to my parents' house for about $120 apiece or take the Prius on one tank of gas. It's 375 miles door-to-door; easily within reach for Priapus. Round trip: $60 with gas left over.
     
    #12 TonyPSchaefer, Feb 12, 2008
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