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What’s this pulsing noise please?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by C Wagner, Aug 14, 2021.

  1. C Wagner

    C Wagner Member

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    https://youtube.com/shorts/2t0kfaSUKy0?feature=shareCan anyone help with this pulsing “zoop/zoop”noise from the engine compartment? TIA

    car: gen 2 2004 Prius. 170k. Has both coolants oil and fluids topped off. inverter seems to agitate coolant ok. No error codes. Water pump replaced 3K ago, engine coolant changed then when the car was new to me. Mostly hear it at low speeds when moving and after stopped. Hoping it’s semi to very normal.
    Video:https://youtube.com/shorts/2t0kfaSUKy0?feature=share
     
    #1 C Wagner, Aug 14, 2021
    Last edited: Aug 14, 2021
  2. nancytheprius

    nancytheprius Active Member

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    my 06 makes the same noise and always has! 78k miles. Ive searched for it too and i think it’s a coolant pump but let’s get another opinion haha
     
    #2 nancytheprius, Aug 14, 2021
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  3. JC91006

    JC91006 Senior Member

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    It's the coolant 3 way valve, change it and the noise will go away
     
    #3 JC91006, Aug 14, 2021
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  4. C Wagner

    C Wagner Member

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    Thanks! How long do I have before it becomes serious? I’d like to drive it a couple hundred miles before fixing.
     
    #4 C Wagner, Aug 14, 2021
  5. ChapmanF

    ChapmanF Senior Member

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    Even without clicking the video, I read that and thought "coolant control valve". :)
     
    #5 ChapmanF, Aug 14, 2021
  6. JC91006

    JC91006 Senior Member

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    It won't really affect the car even if it goes bad, you'll just get a check engine light and possibly no heater.. But the car won't break down because of this issue.
     
    #6 JC91006, Aug 14, 2021
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  7. C Wagner

    C Wagner Member

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    Thank you / very helpful. I’ve also learned that I can do the valve and the inverter pump (which I purchased in a fit of zealousness) together by pulling the drivers headlight!
     
    #7 C Wagner, Aug 14, 2021
  8. JC91006

    JC91006 Senior Member

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    Well if the inverter pump has not failed, I would just leave it alone. If the sound doesn't really bother you, you really don't even have to address the 3 way valve until you get a check engine light.
     
    #8 JC91006, Aug 14, 2021
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  9. ChapmanF

    ChapmanF Senior Member

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    or a cold snap with no heat
     
    #9 ChapmanF, Aug 14, 2021
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  10. C Wagner

    C Wagner Member

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    Dare I divert my thread? What else will go bad on a 170k Prius gen 2? I think I’ve got the 12v (and water into the back) under control, the flopping visor, the HV battery, water pump, engine oil, rear struts, gas tank straps all under control - mostly because i had to replace those. I’ve got a PCV and new plugs but not installed them yet. I had a cat converter theft deterrent installed. I just had to repair the tailgate cover, which broke off in my hands - button itself works ok. Does anyone get water pooling in the driver A column?
     
    #10 C Wagner, Aug 14, 2021
  11. JC91006

    JC91006 Senior Member

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    170k miles is considered low mileage. Your next repairs will probably be combination meter replacement and brake actuator replacement. Those are sure to come up on an older Prius. At this point, you tackle all the issues as they come up. And they will all come up, just like any other 15 year old car.
     
    #11 JC91006, Aug 14, 2021
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  12. dolj

    dolj Senior Member

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    ... and you'll be doing the hybrid vehicle (HV) battery again soon, if that replacement you mentioned was not a brand new battery with brand new modules (or at least brand new (or nearly brand new) set of modules swapped to replace the old modules),
     
    #12 dolj, Aug 14, 2021
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  13. C Wagner

    C Wagner Member

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    How soon again will I be working on my HV battery? I'd love to get an idea of how long a decent repair and balance (I think my job was decent, based on what I've read here) will last. I've tested it with Dr Prius after the reinstallation and battery health per that app is still good after 10 months.
     
    #13 C Wagner, Aug 17, 2021
  14. dolj

    dolj Senior Member

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    A decent repair might last up to 2 years, but we often see 6 to 18 months frequently reported here. It really depends on how well the job is done, and some owners spend a lot more time on it and get a better job as a result. Keep monitoring it with Dr. Prius as that should give you a good feel for how your battery is going.
     
    #14 dolj, Aug 17, 2021
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  15. C Wagner

    C Wagner Member

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    18 - 24 months would be less than I'd hope for, but I'll update how battery health goes in my car's case.

    As for a failing battery that someone wants to at least partially 'fix', is there any way to do an on-car semi repair, such as bulk charging the entire battery up to some point, or perhaps (dreaming here), clearing the codes and charging the battery up from the ICE in service mode, or down a long hill, followed by depleting the entire battery by stealth mode or similar -- and then repeating the up/down cycle? In my case, 4 modules were just bad bad and this 'bulk charge' probably wouldn't have helped long term, but maybe a brand new red triangle could be lessened?
     
    #15 C Wagner, Aug 17, 2021
    Last edited: Aug 17, 2021
  16. ChapmanF

    ChapmanF Senior Member

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    After my Gen 1 was of a certain age, I caught it doing exactly that kind of thing all on its own from time to time.

    I've never caught a Gen 2 or Gen 3 in the act yet, but I guess I would be surprised if they don't know how.
     
    #16 ChapmanF, Aug 17, 2021
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