Loud ticking, battery only charges halfway, with slightly elevated coolant temp.

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by FALC0N, May 25, 2026 at 2:50 AM.

  1. FALC0N

    FALC0N New Member

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    A few days ago, my 2008 Prius developed a loud ticking sound, which is apparently coming from the gas engine as it only appears when the gas engine is running. Around the same time, I noticed the hybrid battery wouldn't charge more than halfway, no matter what driving pattern I used. I also notices engine coolant temp was a bit high.

    Normally, engine coolant temp rarely goes over 190 for any reason. But I since the ticking, it has started floating a bit high when at a stop, with or without the gas engine operating. It's not much, with 199 being the highest reading I have registered, but that is still unusual in my experience.

    Otherwise, the car still drives mostly normal. No indicator light of any sort. My OBDII reader is a super simple thing, but it registers no codes.

    Has anyone encountered this before, or have any ideas what it might be?
     
    #1 FALC0N, May 25, 2026 at 2:50 AM
    Last edited: May 25, 2026 at 2:59 AM
  2. pasadena_commut

    pasadena_commut Senior Member

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    Check that the water pump belt is still there and looks OK. If that isn't it, record the sound and post it here.
     
    #2 pasadena_commut, May 25, 2026 at 3:46 PM
  3. JC91006

    JC91006 Senior Member

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    I have encountered the battery not charging properly and that usually is caused by engine not producing enough power. In my case, I had a misfire caused by bad spark plug. So I suggest you look into the condition of your spark plugs and Coils, to make sure there isn't a misfire.
     
    #3 JC91006, May 25, 2026 at 4:06 PM
  4. PriusCamper

    PriusCamper Senior Member

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    Sounds like two entirely seprate problems... Have you been losing coolant? Please do what @pasadena_commut asks... As for your battery charge level. Get an OBD2 reader: http://www.ebay.com/itm/265484403768 and use Dr. Prius Chat and post some screenshots.
     
    #4 PriusCamper, May 25, 2026 at 4:50 PM
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