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Fan noise coming from rear passenger side.

Discussion in 'Prime Care, Maintenance and Troubleshooting' started by socalguy1, Jul 9, 2017.

  1. socalguy1

    socalguy1 New Member

    Joined:
    Jun 3, 2017
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    Location:
    Socal
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    I've had the prime prem since mid feb, but only started really driving it in June, when I sold my 2006 prius. It currently has less than 2500 miles.

    I'm getting between 29-30 miles per charge. My commute is approximately 26 miles each way, so I'm in 99% ev mode. I charge up at my work place and at night.

    I get this terrible, broken bearing, fan noise coming from the rear passenger seat when I've depleted or come close to depleting the ev battery.

    I brought it into the dealership last Thursday, and they could not reproduce the noise. They had it for TWO days. They said they ran the traction battery fan through the different speeds and "it all checked out."

    I took the car back Friday evening and decided I would go through my commuting routine Saturday at noon, at peak temps. It's currently 90's in socal.

    Well, the noise came on after I depleted the ev battery and HV mode kicked in. This time I recorded it on my phone, but its a video or else I would load it up for you guys (~300 mb).

    I drove it directly to the dealership and got one of the head techs to ride with me to experience it for himself. He came up with the same conclusion: likely a bad battery fan. He made it clear to me that he was not involved in the original visit, that supposedly cleared the fan of any defect.

    By the way, I took the car on a 300 mile trip in April and never heard it, but I think I was in HV mode and never really in ev mode or depleted the ev battery.

    Conceivably, the battery temp my never reach it's peak and the fan may never ramp up if you're in HV mode or you never go total EV and deplete the battery.

    Anyways, I just wanted to help any Prime owners in the future with a weird fan noise coming from the backseat. They are sometimes defective or go bad.

    I'm also curious if prime owners with a similar driving routine have experienced this.
     
    HPrimeAdvanced likes this.
  2. HPrimeAdvanced

    HPrimeAdvanced Senior Member

    Joined:
    Mar 2, 2017
    2,301
    3,517
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    Location:
    Anaheim, CA
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Advanced
    I do hear a fan sound and A/C runs when I approve A/C operation during charging on my Advanced, when it's hot. The sound is subtle, and the advantage of charging in this mode is the car is cool if interrupted during charging. I haven't heard a grinding sound, so it appears that all is fine. It does appear to increase charging time by 50 minutes.

    .
     
  3. socalguy1

    socalguy1 New Member

    Joined:
    Jun 3, 2017
    4
    6
    0
    Location:
    Socal
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    Just an update:

    They said the cause of the fan noise was a loose plastic fastner that would get caught in the fan when the fan turned on to cool the battery. It was likely an error during assembly in Japan.

    The dealer said the fan was fine to use, but they are still ordering the fan unit to be replaced just in case. The part has to be ordered from Japan, and they do not have an ETA for the part.

    They released the car to me. Problem solved. No more noisy fan.
     
  4. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
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    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    interesting, never heard that one before. sounds like a good dealer.(y)
     
    HPrimeAdvanced likes this.
  5. Jeff Cohen

    Jeff Cohen Junior Member

    Joined:
    May 3, 2017
    18
    12
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    Location:
    Dallas, TX
    Vehicle:
    2003 Prius
    Model:
    Base
    My battery fan may be running unnecessarily too. I just drove to lunch (retired) and back, went to plug it in at 7:30 pm and heard it running. Restaurant was only 10 minutes away, the AC was on at 77 F and 2 people aboard. City streets. 2nd time. 1st was Tuesday evening after running around town a bunch. On and off the expressway. Mid 90s. Two people aboard. AC set to 77 F. Battery drained quickly on way home, Message about traction battery temperature being high. Smell of hot electronics. You can't hear the fan while driving, if it was running. I think having the AC default to recirculate may starve the battery cooling system of fresh air. What are the risks? Fire? Weaker battery? Premature battery death?
     
  6. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
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    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    no risks, battery management system takes care of everything. the battery doesn't need 'fresh air', it's not a biological. cool air is the most it can ask for. recirc is the best way to go.
    otoh, you may want to take it in to check for a 'loose plastic fastener'.
     
  7. Flaming

    Flaming Active Member

    Joined:
    Aug 9, 2017
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    Location:
    QC , Canada
    Vehicle:
    2017 Prius Prime
    Model:
    Technology
    The only fan noise i heard so far is the fan noise coming from the charger under the back seat when i charge the car.
    I know my car is '' new ''... only 1 550 Km on the Odo but but until now I have no idea kind of noise the traction battery fans make. ...

    it should be noticable because there is two of them , one each side of the battery
     
    john1966 likes this.