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Strange noise when starting

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by ny biker, Apr 7, 2008.

  1. ny biker

    ny biker Member

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    This started happening a week or so ago. When I first start the car in the morning, I hear an unusual noise, kind of reminds me of someone tapping out morse code. It lasts for a few seconds and then it stops and the engine turns on like normal.

    No warning lights, car seems to drive normally.

    It only happens on cold startup in the morning. I don't hear it any other time, including when I start the car to go home from work (after it's been sitting all day).

    I park outside at home. Temps around here have been in the 40s at night, 50s-60s during the day.

    May or may not be relevant: The parking lot at home has a slight slope to it. I back into the space so the front of the car is slightly elevated compared to the rear. I only thought of this while I was driving to work today so I haven't been able to test it to see if the noise happens when I park front-in. (I doubt this is related but I was trying to think of differences between when I hear the noise and when I don't, and since the parking lot at work is flat...)

    The car has 9500 miles on it. I'm about to take the car in for an oil change and safety inspection. I want to mention the noise to them but since I won't be able to reproduce it for them I was hoping someone here might have some input as to the cause, or could at least tell me what the car does as soon as you power on so I can sound a bit more intelligent when I'm talking to the service guys about it.

    Thanks!
     
    #1 ny biker, Apr 7, 2008
  2. qbee42

    qbee42 My other car is a boat

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    Is this tapping different than the rattle from the brake accumulator pump? That one sounds like a ratchet down in the driver's footwell, and sometimes it will actuate when you power up.

    You also get the coolant transfer pump running when you power up. This should be more of a whirring sound, but it can squeal when it gets cold and old.

    Tom
     
    #2 qbee42, Apr 7, 2008
  3. ny biker

    ny biker Member

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    It's definitely not a whirring sound, or a squeal.

    Maybe it's the brake accumulator pump. It does seem to be coming from the driver's side front.
     
    #3 ny biker, Apr 7, 2008
  4. qbee42

    qbee42 My other car is a boat

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    Listen carefully when you press the brake pedal. About every third time or so the pump will activate. If things are quiet in your car, you can hear it.

    Tom
     
    #4 qbee42, Apr 7, 2008
  5. ny biker

    ny biker Member

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    Normally I turn the stereo on just before shifting into Drive, so it's not usually quiet most of the time I'm in the car. I have turned the sound down while driving a couple of times recently since this noise started happening after powering on, and didn't hear anything unusual, but now that I know more about what I'm looking for I'll leave the stereo off and play around with it.

    Also now that you've given me a good term to search for, I found the TSB from last February.

    Thanks!
     
    #5 ny biker, Apr 7, 2008
  6. alanh

    alanh Active Member

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    When I start up, there's a bunch of clicks from relays engaging.
     
    #6 alanh, Apr 9, 2008
  7. icesalmon

    icesalmon Junior Member

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    My 14 month old (25k miles) started to make same kind of noise 3 months ago. Have you got yours fixed?
     
    #7 icesalmon, May 26, 2008
  8. Jared

    Jared Member

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    Probably the clicks from the relays. I hear them every time I start, but you may not have noticed them before.
     
    #8 Jared, May 27, 2008
  9. qbee42

    qbee42 My other car is a boat

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    Relay clicks are quick and then done. The brake accumulator pump runs for about three seconds, and is more of a buzzing or ratcheting sound which comes from the driver's footwell. If it is the brake accumulator pump then it is normal and there is nothing to fix.

    Tom
     
    #9 qbee42, May 27, 2008
  10. TSFlyer

    TSFlyer New Member

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    I have around 9,800 miles on my '07 Prius.

    I've just recently started experiencing the same ticking noises described in this thread and like the original poster's experience, they only appear at cold startup in the morning. Morse code sounding ticking is a good description.

    I never have the stereo on when starting up and have been keenly aware of the normal noises the car makes. This is different.

    I've posted a short video of the noises at:
    Prius Noise

    I'd much appreciate it if someone can take a look and tell me if this is considered "normal"...

    Thanks very much.

    TS
     
    #10 TSFlyer, Jun 2, 2008
  11. Patrick Wong

    Patrick Wong DIY Enthusiast

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    That is the sound of the engine coolant heat recovery pump working to move hot coolant from the thermos container into the engine, which is a pollution-control activity. The sound is normal.
     
    #11 Patrick Wong, Jun 2, 2008
  12. TSFlyer

    TSFlyer New Member

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    Thanks for the reply Patrick.

    I'm curious why the sound would only show up around 9,500 miles. Like I mentioned before, I'm keenly aware of the different sounds of the Prius, but the heat recovery pump ticking is a new one for me, even if it is normal.
     
    #12 TSFlyer, Jun 2, 2008
  13. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Hi TS,

    Well - either you are now more aware of the various sounds that are being made; or the pump may be noisier now, than when new. Others have complained about a noisy pump.

    Some owners have been able to get the pump replaced under warranty, while other dealer service depts say this is normal, don't worry about it. If the noise bugs you, then I suggest you consult with your dealer's service writer.
     
    #13 Patrick Wong, Jun 2, 2008
  14. ny biker

    ny biker Member

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    In my case, I was always aware of a noise when starting the car, but one day I noticed the sound was different. Instead of a steady hum/whine it's intermittent/stuttering.

    However since it only happens on a cold start I won't be able to demonstrate it for the dealer. So I'm waiting to see if it gets worse. Maybe next winter when temps drop it will happen more often and I can show the dealer. I've still got almost 2 years on my warranty.
     
    #14 ny biker, Jun 3, 2008
  15. Jared

    Jared Member

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    The Prius makes all sorts of strange noises, but it has worked perfectly for 65k so I don't worry about it.
     
    #15 Jared, Jun 3, 2008
  16. TSFlyer

    TSFlyer New Member

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    Yes, exactly my experience. This is why I recorded the sound/video (posted a couple posts up). I'll show that to the service tech.

    Jared, I'll give you that the Prius makes strange noises, but I can't be totally complacent about this new noise until my dealer's service tech confirms/clears it for me as well.

    Thanks again.

    TS
     
    #16 TSFlyer, Jun 3, 2008
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