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Jerky acceleration in the summer heat

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by rtotheichard, Jun 21, 2016.

  1. rtotheichard

    rtotheichard Junior Member

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    Hey, all.

    My 2012 Prius Two did something odd today that it's never done before and I'm curious if anyone can shed light on it, or has experienced something similar.

    Today, after leaving a meeting, I had two instances where accelerating from a complete stop was met with a delay followed by a jerky and sudden acceleration. This only happened twice out of the dozen-or-so complete stops I made. This only happened on my first couple of complete stops, then never did it again.

    Here is some pertinent information:
    - Silver Prius, no tint
    - Car sat uncovered for about 2.5 hours
    - Was 96 degrees outside, not a cloud for miles
    - Turned the car on, opened the front two windows to help hot air escape
    - Turned the AC on to full
    - Sat parked but car running for maybe 30 seconds before reversing out of parking spot
    - Rolled up windows
    - Battery fan was going strong
    - No indicator lights came on to suggest an issue
    - Happened on my first two complete stops at stop signs
    - Never happened again
    - Battery fan eventually simmered down
    - Have 55,000 miles on the car
    - Tacos are my favorite food
    - Boba tea is delicious once you get used to it


    Thanks to anyone who can help diagnose this issue, or give any information!
     
    #1 rtotheichard, Jun 21, 2016
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  2. bisco

    bisco cookie crumbler

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    i would start with the battery cooling fan, make sure it's clean, and get front and rear window shades for parking in the sun. if the battery overheats, the computer won't allow use, so you're on tiny engine power alone, until the a/c cools down the battery.
     
    #2 bisco, Jun 21, 2016
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  3. Mendel Leisk

    Mendel Leisk EGR Fanatic

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    I've seen my fan go up to speed 4 (out of 6?), with ScanGauge, but have yet to hear it. So if you're hearing it, I'd say not good. I've also monitored battery temp with SG, and worst case is when the car sits in hot sun after a drive for a bit, when you hop back in and start it up.
     
    #3 Mendel Leisk, Jun 21, 2016
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  4. rtotheichard

    rtotheichard Junior Member

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    The fan is clean and is never blocked. I'll look into shades and also leave the windows cracked a bit when out in the sun. Are there any shades you recommend? Thanks!

    Whenever the fan comes on, I hear it, even if it is on the lowest setting. I attribute most of it to my obsessive compulsive disorder (I'm diagnosed and notice the smallest of things).

    Any idea how much the average battery diagnosis costs from a dealership?

    Thanks again, all!
     
    #4 rtotheichard, Jun 21, 2016
  5. bisco

    bisco cookie crumbler

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    i don't park in the sun very often, so no shades. check the priuschat shoppe, some people seem to like them.

    the dealership will charge the one hour minimum, whatever the hourly rate is. $100. wouldn't surprise me.

    it's okay to hear the fan, that's not unusual.
     
    #5 bisco, Jun 21, 2016
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  6. rtotheichard

    rtotheichard Junior Member

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    Thanks for the replies, bisco. I've always considered you a valuable member of this community, and I recall you helping me out in the past with some things. So, kudos.
     
    #6 rtotheichard, Jun 21, 2016
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  7. CR94

    CR94 Senior Member

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    It is very quiet at its lowest speed(s). Normally I hear it only when it's coasting to a stop just after I press the POWER button to shut down the car. Sometimes on hot days I can barely hear it running with the car still READY, if everything else is stopped, there's no outside noise, and I lean back from the driver's seat as far as I can toward the fan inlet.

    Did you get a reading on battery temperature during that episode of "jerky acceleration"? I haven't seen it exceed 109°F (~43°C) since I set up that "X-Gauge" on my ScanGauge. Somewhere in this site there's a post showing the specifications for fan speed vs. battery temperature.
     
    #7 CR94, Jun 21, 2016
  8. Former Member 68813

    Former Member 68813 Senior Member

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    simple, the battery got too hot and you lost the battery assist. you must change what you're doing to the car. i'm not sure what that is. maybe the tacos?
     
    #8 Former Member 68813, Jun 21, 2016
  9. rtotheichard

    rtotheichard Junior Member

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    I just ordered a scanner so I'll be able to test it Thursday.

    That sounds like the problem! I think the thing I can do differently is let the car cool down a tad more on these significantly hot days. And park in the shade. And crack windows. And get some shades for the car.

    I'll never give up the tacos. From my cold, dead hands!
     
    #9 rtotheichard, Jun 21, 2016
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