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Loud metallic slapping sound when driving over lane reflectors - AUDIO RECORDING NOW INCLUDED

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Preeeus, Aug 9, 2016.

  1. Preeeus

    Preeeus Member

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    Our 2010 Prius makes a loud metallic slapping sound whenever we drive over the lane marking reflectors on the roads.

    Here is a sample of the sounds it generates: Toyota Prius Loud Slapping Sound when Driving over Lane Refl... - Clyp

    We have just a few hundred miles left on our Toyota Platinum extended warranty, and want to get this fixed if it's indicative of a problem.

    We first took our Prius to an independent mechanic for a free quick evaluation. They thought it was perhaps metal clips on the hubcaps, but taking the hubcaps off made no difference. No cost, no problem.

    Then we took it to the nearest Toyota Dealership since any extended warranty repairs have to be performed by a dealer. They performed several inspections (including one of the undercarriage and another of the brakes), charged us a bunch, but found no issues.

    We then insisted on a test drive with their head mechanic, who heard the loud noises, and said that wasn't normal. Without apparently knowing that the brakes had already been inspected by his team, he said he recommended getting the brakes checked. Once we returned from the test drive, he learned from the Service Advisor that the brakes had already been inspected. He then said "Since the brakes were inspected, and no problems were found, there is no issue".

    We called another Toyota Dealership, and they want $120 to try to diagnose the issue. But we have already invested too much money on unhelpful Toyota inspections with nothing to show for our money.

    So we are desperately turning to the kind people here.

    Anyone know what this issue could be? Anyone else ever experience it? Any solution?

    (Oh, btw, that's not our Prius in the photo.)
     
    #1 Preeeus, Aug 9, 2016
    Last edited: Aug 21, 2016
  2. Jimi1976

    Jimi1976 Active Member

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    How about when hitting a regular bump (i.e., not a lane marker)?
    Do you feel it in the car at all?
    Is it a "clunk"? Could be front sway bar bushings....or end links....or both. Either one is a very easy repair of you're handy. If not....maybe covered under warranty?
     
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  3. Raytheeagle

    Raytheeagle Senior Member

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    The noise is only present when traversing lane markers? No other surface will elicit the noise recurrence? Experience any drive ability issues when the noise is present? What about at different speeds? Oh and nice pic of the Prius by your name:).
     
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  4. Preeeus

    Preeeus Member

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    Thanks Jimi. Great questions. We don't hear anything unusual when hitting a regular bump. When we go over lane markers, we hear the slapping sound, but don't feel anything unusual in the car (we do feel the slight bump caused by the markers). A "clunk" doesn't really describe the sound well... much more like the sound generated when slapping two pieces of thin sheet metal together.

    Thanks Ray. More great questions. Correct, no other surfaces have elicited the noise. But when going over lane markers, it's not subtle! If the road is narrow, and there are buildings nearby, we can hear the sound echoing off.

    No driveability issues when the noise is occurring that we have noticed. We have noticed the loud slapping sound at all speeds over about 5 MPH.

    Thanks for the compliment regarding the photo. That's actually not our Prius, but we love that pic too!
     
  5. Raytheeagle

    Raytheeagle Senior Member

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    I will keep the questions coming;). What area of the car do you hear it coming from? How long have you noticed the noise? Any recent maintenance performed?

    It's not the hood prop rod not placed in it's clip? I had that happen once coming back from the dealer:confused:.

    Since you said it sounds like sheet metal pieces hitting, maybe you could safely take some audio. Trying to think where 2 pieces of metal would be rubbing together. There's nothing loose in the seats or cabin area like a flashlight hitting against a seat support?

    I bet that Prius would make some of our modders here jealous:)
     
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  6. Jimi1976

    Jimi1976 Active Member

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    Solid point about the hood prop.....happened to me a few weeks ago. Worth a quick check.
    I would suspect a suspension issue (links, bushings, struts).
     
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  7. Raytheeagle

    Raytheeagle Senior Member

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    Could be possible, but I would think you could replicate that on other scenarios. If it's not causing any drive ability issues it might be a sanity question then:mad:.
     
  8. Jimi1976

    Jimi1976 Active Member

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    Have you ran over the same markers with another car? Maybe it's just the sound they make?
     
  9. Preeeus

    Preeeus Member

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    It's hard to tell where it's coming from. Definitely not inside the cabin or from the roof! Also, does not sound like it is from the engine compartment.

    Now, this is very hard to estimate (and don't want to bias anyone's thoughts), but it sounds like it is coming from about the height of the axle, perhaps near where the wheels attach to the axles. But it doesn't particularly sound "front" or "rear".

    Very unlikely given the loudness, but we will definitely take a look.

    Yes, we will try to record some audio with a cell phone. Does that count as using a cell phone while driving?

    That's an easy one... definitely nothing loose in the seats or the cabin area. Rolling down the windows makes the noise sound much louder.

    Yes, makes us jealous too! ;-)
     
  10. Preeeus

    Preeeus Member

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    When the independent mechanic took a quick look at our Prius, she said she noticed a torn rubber boot cover. She didn't see any fluids leaking or anything like that. Any idea what type of boot cover she might have been talking about? Is it meaningful or need repair? Note that after extensive inspections, the Toyota Dealership never even noticed the torn boot cover.

    Good question. Did it. Ran over the same markers in another car. The markers themselves definitely don't make any sounds, and the other car was almost silent while running over them. The Prius, on the other hand: "CLACKITY CLACK SLAPPITY SLAP".
     
  11. Jimi1976

    Jimi1976 Active Member

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    CV boot.
    Could be torn
     
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  12. Preeeus

    Preeeus Member

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    Would that account for sounds like described above?

    If the rubber boot cover is torn, does it need to be replaced... or is it something that is basically a non-issue?
     
  13. Preeeus

    Preeeus Member

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    BTW, watching
    right now, which so far (only a few minutes into it), is making it sound like the whole axle could need replacement. That's a terrifying thought.

    Although what he is describing is more like the other "concerning noise question" we posted a little while ago (as opposed to the noises described in this thread).
     
  14. Jimi1976

    Jimi1976 Active Member

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    A torn boot will leak grease, possibly causing the cv axle to come loose, causing some noise.
    A cv boot is like $15, plus $1 in grease, so to have a shop make this repair is all labor.
    I'd have your shop take another look at the torn boot they found, and chat with them about the noise.
     
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  15. Preeeus

    Preeeus Member

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    Thanks Jimi. BTW, we posted something right above your reply while you were typing.
     
  16. dorunron

    dorunron Senior Member

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    Here's my .02 on the subject.

    I have seen strings like this before on the subject here on PC discussing this same thing. (Noise when going over road turtles, changes in pavement, etc.)

    I also regularly from day one of ownership of our bought BRAND NEW 2013 Model Three have heard and sensed what is being discussed in this string. The easiest way to make the Prius do it's thing is to drive over the white reflective things on the stripes of the road at about 30 miles an hour or so. You definitely wants your windows down and the radio OFF.

    After tolerating this for a long time, I too started to investigate it. I had it looked at by Toyota and they could not determine what it was. The final word was it is normal since they drove another Prius that is doing the same thing (brand new on the lot). This was last spring I believe (2015).

    Since then I have had my regular services and have never had anything pointed out as being broken, out of spec, or flawed.

    It was real funny watching the tech's try to figure this out. At one time there were five different tech's in the car along with the supervisor. None of them could find the offending item.
     
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  17. Raytheeagle

    Raytheeagle Senior Member

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    On my 2010 that I have owned since mile 7 gone with 137 k and counting, I noticed several years ago the boot on the front shocks were torn. That is to keep dirt out of the shock. Never done anything about it, just know it's there.

    It is probably that boot that she was referencing as it is probably very common, maybe too common for the dealer to notice:(.
     
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  18. qdllc

    qdllc Senior Member

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    I'd check the brakes with someone better. They may have "looked" at the brakes but not "inspected" them. If something is loose, you might not see it, but you'd feel it or hear it if you tap different parts of the assembly to ensure everything is tightened down properly.
     
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  19. MrMischief

    MrMischief Active Member

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    Are you talking those little flappy stand up plastic reflectors they put down as lane markers?
    [​IMG]

    They make a flapping sound when you drive over them in any vehicle. Maybe the lack of sound deadening in the Prius makes it more noticeable?
     
  20. Jimi1976

    Jimi1976 Active Member

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    Look under the car. Front.
    Horizontal boots on axles. Those hold grease. Do they appear to be torn?
    Strut boot covers are VERTICAL....and can be viewed from the outside of your wheel well. Those are dust covers, hold no grease, and can be noisy of torn (flapping around). Not a common thing for a basic road vehicle....but not unheard of
     
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