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Noise at start-up in HV mode

Discussion in 'Gen 1 Prius Plug-in 2012-2015' started by Tabor M, Aug 5, 2015.

  1. Tabor M

    Tabor M Junior Member

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    When I start my car in HV mode (not enough juice to drive in EV mode), I've noticed this noise sounding like the motor is starting. The noise lasts about 15 seconds and quiets down. When the noise is on-going, the EV and ECO sign on the instrument panel would only show a silluete (it doesnt light up to show the EV or ECO). Once it quiets down, the "EV" sign lights up.

    I dont think this has to do with warming up the car because it's 85F outside where it's parked...

    This doesnt happen when my car is fully charged and driving in EV mode.

    Does anyone have noticed or experienced this?
     
    #1 Tabor M, Aug 5, 2015
  2. Tracksyde

    Tracksyde Member

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    It sounds like its your engine starting up (this is how a regular Prius would work). Even though its 85F outside, the engine isnt "warmed-up" unless the coolant temp is at 130F (in Eco mode) or 145F (non-Eco mode).. (not positive about the coolant temp numbers, thats from memory.. but I think its right)
     
    #2 Tracksyde, Aug 5, 2015
  3. Tabor M

    Tabor M Junior Member

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    Thanks! There were times I was driving in EV mode and decided to switch to HV to save the EV for the local drive later. The "start-up" came up shortly after i made that switch while driving. Is that normal?
     
    #3 Tabor M, Aug 5, 2015
  4. Tracksyde

    Tracksyde Member

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    Yes, that's normal. Once you switch into HV (when the engine is cold), its going to start the engine and get it warmed up. If you hit the button to switch back into EV mode, the engine will continue to run until it reaches that "warmed up" threshold. At that point, if you're in EV, the engine will shutdown.

    If you know ahead of time you want to switch to HV at some point so you can save some EV for later, try doing it at a stop light while you're waiting. The engine warms up much faster if you're not moving (so no moving air to cool down the engine and radiator). Some of the more hardcore members here will even block their grill to keep the engine warmed up longer and to decrease warmup time (although I think most of them are in colder climates).
     
    #4 Tracksyde, Aug 5, 2015
  5. Tabor M

    Tabor M Junior Member

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    Got it! Thanks so much!
     
    #5 Tabor M, Aug 5, 2015
  6. Tabor M

    Tabor M Junior Member

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    Then....what if i've been driving in EV mode for a few good miles, and decided to switch to HV and continue on free way? Would that cause any trouble for the engine?
     
    #6 Tabor M, Aug 7, 2015
  7. bisco

    bisco cookie crumbler

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    probably not, but for longevity, it might be better to hit hv a few minutes before, so it can warm up a little. you won't get much power from a cold engine. depending on outside temp of course.
     
    #7 bisco, Aug 7, 2015
  8. Tabor M

    Tabor M Junior Member

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    so...the temp took a dip today to 60 F...I was driving in EV mode locally...then I felt the "start-up". Would it be a good idea to start out in HV, and have it warmed up first, then switch to EV to drive?
     
    #8 Tabor M, Aug 10, 2015
  9. bisco

    bisco cookie crumbler

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    nope. if you watch your battery meter, you'll know when the 'start up' is coming. when the battery gets low, the engine starts, that's what it's designed to do. otherwise, you'll be sitting on the side of the road, waiting for a tow truck. why does this freak you out?
     
    #9 bisco, Aug 10, 2015
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