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ICE Shutdown causes surge/jolt forward

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by leghk, Feb 19, 2013.

  1. leghk

    leghk New Member

    Joined:
    Jun 13, 2012
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    Vehicle:
    2010 Prius
    Model:
    Three
    I did quite a bit of searching, and found similar problems but under very different conditions, so I hope this topic hasn't already been covered.

    I have a Gen III Prius 2010 with about 50k on it. I've noticed over the past month that when the ICE shuts down at a stoplight, the car will surge forward a bit. If my foot isn't on the brake really hard, it will translate to the car actually moving forward until the ICE is totally off. If my foot is on the brake hard, you can feel it push against the brakes, and then the car settles back in place. It doesn't happen every time, so it still takes me by surprise.

    I live in a cold weather environment, and it's been pretty cold for the past month. So the cold may be a factor. I believe this issue occurs more often when the engine is not fully up to temp (e.g. in the warm up cycle, but still willing to shutdown when at a complete stop), but I'm not totally sure of that.

    Is this just the computer not able to perfectly compensate for the ICE shutdown using MG1 because of the cold weather causing unpredictability? This is definitely a problem I can live with, the surge isn't so bad I fear smashing into the car in front of me, it's just a bit freaky. However I only have a few more months on my certified-used warranty, so if this is an actual issue (and going to get worse), I would like to get it looked at before then. Anybody else run into this?
     
    #1 leghk, Feb 19, 2013
  2. Yannick

    Yannick Junior Member

    Joined:
    Aug 24, 2012
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    Vehicle:
    2012 Prius
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    Mine does something similar; I took it to the dealer to check it out and they found nothing. Gen III 2012 Prius with 14k km on it.

    Like you, it only happens in cold weather (-10C or below) when stopping before the car is fully warmed up, OR just coming off the highway. (Something's getting cold from highway windchill?) The engine keeps running for a second or so after the stop, and then it feels to me like it stalls. There's a shudder that rocks the car on its wheels a bit, although I don't feel a preference for forward or backward.

    I lean to attributing it to hybrid quirks that we're just not used to yet.
     
    #2 Yannick, Feb 23, 2013
  3. The Critic

    The Critic Resident Critic

    Joined:
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    Vehicle:
    2011 Prius
    Model:
    Three
    Mine does it as well, though it does seem to be more apparent as more miles accumulated. It probably has something to do with the mounts wearing, if I had to guess? I am at 57k.
     
    #3 The Critic, Feb 27, 2013
  4. edthefox5

    edthefox5 Senior Member

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    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    Yeah its unhappy. In a more temperate environ the engine shuts off way before you stop at the light so you never feel that. Your engine is so cold its still running when you come to a stop even though you let off the gas pedal a ways back.

    I bet the car is not garaged either so will take a good drive to really warm it up.

    Best fix that will help is use Mobil 1 0-20 Synthetic motor oil and grill block the front of the car. Grill blocking is very easy. Safest way to do that though is to buy a Scan Gauge that will monitor engine temp so you can see if your blocking too much or not enough. The main beny's is you get your mileage back and your engine runs better. Your mileage is tanking in this cold.

    Most of us on here own a Scan Gauge or version of one. I have both a Scan gauge and a Droid with Bluetooth Kiwi PLX OBDII cable.
     
    #4 edthefox5, Feb 27, 2013
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