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
  5. JC91006

    JC91006 Senior Member

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    I’ve had a car that would tick loudly when the engine is on, that engine was damaged due to oil starvation. The compression was low on it and it didn’t charge the battery easily, probably due to low power.
     
    #5 JC91006, May 25, 2026 at 7:51 PM
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