Longer Idle at startup or "How long is normal?"

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Starhopper68, Jun 6, 2021.

  1. Starhopper68

    Starhopper68 Junior Member

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    Advice or observations, please. So I've owned my 2011 for 6 yrs and I've put 98K miles on it (141 K total) and it's always run great with great mpg. After sitting overnight it never used to idle after going into ready mode. (Unless of course it was cold out and had temp control on.) That's slowly changed. Probably a yr or so ago it would briefly turn on and then off but now it will idle for about a minute before shutting down. (And to be clear the SOC is usually 50-60% so it's not at the 40% when it usually turns on) So fearing the battery was going bad I got an OBDII and did the Dr. Prius tests. Passed both with no codes or problems and was pleasantly surprised with the 3 life expectancy tests - 75, 75, and 77%. But I did notice one of the 14 packs is consistently lower than the rest while in battery monitor mode so I'm assuming that's why it's idling: to get them sufficiently balanced. Or is the idling possibly something else?

    Not sure what to do. I'd like to keep it another 3-5 yrs but am not sure of the best strategy going forward. Some of the options I've seen are a replacement pack or cell around $50, the Prolong system at $700, a reconditioned $1600, or even possibly the new Lithium replacement $1900 out now or soon. Any other options? Or should I just leave well enough alone and the longer initial idling is nothing to worry about? Hmmm...
     
  2. sLick415

    sLick415 Member

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    It's supposed to idle on the first startup.
    Gen3 warming up stages | PriusChat

    As for your battery pack, what voltage difference are you seeing on the app?
     
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  3. rjparker

    rjparker Senior Member

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    My gen3 engine has always started to warm up after a coldstart Ready. Generally the system will initially ev for ~30 seconds. If I start driving quickly the engine may come on as I drive with less perceived shutter due to road and radio noise. The system can also start the engine for low temperature even in the middle of a trip if necessary.
     
  4. Starhopper68

    Starhopper68 Junior Member

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    Just checked. When not driving it's bounces between .02 and .08. When driving it's all over the place but I think .56 was about the highest I saw during hard acceleration.
     
  5. bisco

    bisco cookie crumbler

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    you might be at the point of a head gasket failure. have you cleaned the egr circuit?
     
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  6. sLick415

    sLick415 Member

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    From what I've gathered, as long as it is generally under 0.30v, your pack is fairly well balanced. A little blip here and there is normal from what I've seen.
     
  7. Grit

    Grit Senior Member

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    If your 12v is deteriorating, the ice will stay on longer to charge it up to operating voltage.
     
  8. hoffeck

    hoffeck Member

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    The 12V battery is charged by the inverter and the HV battery not by the ICE.

    Posted via the PriusChat mobile app.
     
  9. Starhopper68

    Starhopper68 Junior Member

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    I have not. Nor have I changed the plugs or the other preventative maintenance I've seen in the NutzAboutBolts videos. (Besides the transaxle fluid which I changed at 60K) I need to do all those things and your message is a good reminder/incentive.
     
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  10. Mendel Leisk

    Mendel Leisk Underfoot

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    Regardless, the engine WILL have to run longer?
     
  11. bisco

    bisco cookie crumbler

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    try an italian tune up, worked for me
     
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