Metallic clunk when bumps are hit

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by thiswho, Aug 6, 2011.

  1. thiswho

    thiswho New Member

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    brand spankin new to the forums and fairly new to the prius.

    Just recently got a 2011 Prius II and i love it. Only having one issue. Sometimes when i hit a bump with the windows open, i get a metallic clunking noise, but if i hit a bump immediately after it, I don't hear it again. Maybe 5 minutes or so later (not exact at all), If i hit another bump it will happen again. Seems to be on both sides of the car. Car has 5k miles so i'll be bringing in for service next week. Does this sound normal or is it something i need to have looked at?
     
  2. F8L

    F8L Protecting Habitat & AG Lands

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    I hear more of a metallic clinking noise when I hit bumps sometimes. It sounds like loose lug nuts but it's not. I have an ' 05 so it's probably a different noise.
     
  3. GrumpyCabbie

    GrumpyCabbie Senior Member

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    What mileage are you at?

    I'd double check all the wheels are on tight enough etc. Maybe check under the hood to make sure the holder hasn't fallen off its bracket and is rattling on top of the engine. I'd also wonder how hard or fast you're hitting these bumps.
     
  4. Dark_matter_doesn't

    Dark_matter_doesn't Prius Tinkerer

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    Search on this forum for "brake noise" or "chassis noise" and you'll find other accounts of this phenomenon. I have it, but the first try at the dealership failed to fix the problem. I'm going back tomorrow for a second try, but with copies of PriusChat threads for the tech to review. I can create the noise by driving over road reflectors - the rattle is only in the front.

    Some say it's the front brake pads rattling, others have had the front brake guides lubricated or replaced.
     
  5. Dark_matter_doesn't

    Dark_matter_doesn't Prius Tinkerer

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    See above (forum failure?)
     
  6. hyo silver

    hyo silver Awaaaaay

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    My first thought would be to check the spare to see if it's screwed down tight. That may not be it, but it's easy to check, and would save a lot of time searching up front and underneath. Sometimes the tools in the rear tray get loose and clunk around, too.
     
  7. katiesdad7

    katiesdad7 Member

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    I had the same problem and they greased up the caliper pins and the noise went away.
     
  8. rrolff

    rrolff Prius Surgeon

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    The brake pads rattle. You get it also on those roadway 'bots dots' at like 25mph or less. It happens on both sides. You won't hear it if you press the brakes lightly (preload) while going over bumps...
     
  9. Dark_matter_doesn't

    Dark_matter_doesn't Prius Tinkerer

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    Same here. Unfortunately, it took two trips to the dealer to fix the problem. I'm guessing the factory is not lubricating the front brake caliper guides on a number of vehicles.

    In my case, I could physically rock the front calipers up and down with the wheels off before the fix. The rocking motion was slight, but not normal free-play. The tech tried to explain the problem the first visit by insisting that the calipers "float".
     
  10. thiswho

    thiswho New Member

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    Generally not fast or hard. Not speedbumps. I baby my cars so I doubt I could be something from hitting a bump too hard. At first thought I thought it may have been a messed up engine mount, which would also explain the amount that the car rolls when it's put into park, but I guess thats just the way these cars work? Haha used to driving my 07mazda 3 manual more than I am the Prius as this is my dads car. Taking it in tomorrow to get the first 5k mile tire rotation done.
     
  11. car78412

    car78412 Member

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    I turn up the radio. I love sirius. :D
     
  12. Canard

    Canard Member

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    I experience this same phenomenon daily, on the same types of section of road. I'd describe it occurring most often on surfaces that would cause the wheel to move up and down rapidly over a short stroke in succession (ie, a broken pavement surface or railway crossing, but not a sharp single bump or direction change).

    I attempted to capture it on video but I'm not happy with the quality; I'll try again.

    On my last service, I mentioned it to the tech who took a closer look at it. He said that the pads do indeed float, and that would be the reason for both the rattling and the loud "clunk" I get when I change directions (ie, backing out of a parking space, then applying the brakes to shift to D).

    It just sounds so wrong, eh? I don't like it. My non automotive-inclined significant other says "we paid how much for this car, and it clunks worse than my mom's old PT cruiser?" :) It's embarrassing.

    -Iain
     
  13. frodoz737

    frodoz737 Top Wrench

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  14. Canard

    Canard Member

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    As a follow up to this: After 3 separate visits, they finally isolated (and repaired) the problem on my car. Purchased September 2010, ~50 000 km.

    To recap: I noticed a heavy metal-on-metal ticking or clunking noise, with the windows down, traveling over uneven surfaces at speeds below about 60 km/h (so, in the city). I generally don't have the radio on and rarely have the fan on, so any of these little noises stand out.

    Additionally, whenever I started out in the morning, when I back out of my parking space and apply the brakes, there's a loud "bang" coming from I believe the rear brakes. It's repeatable if I move forward and backward a few times, but seems to go away after that (ie, I couldn't repeat it after an hour long drive).

    The parts that were replaced for the Front Brake Rattle were as follows:

    04465-47070 Pad Set, Brake
    04945-47020 Shim Kit, Brake
    04947-42050 Fitting Kit, Brake
    47722-47060 Mounting
    47721-47060 Mounting
    47715-52190 Pin
    47715-12A10 Pin, Cylinder Sli
    47769-50010 Bushing


    The parts that were replaced for the Rear Brake Clunk were as follows:

    04946-47070 Shim Kit, Anti Sq
    04948-47010 Repair Kit, Brake
    04466-47030 Pad Kit, Disc Bra
    04478-47040 Cylinder Kit, Fr

    These changes have completely eliminated both noises, and the car sounds as it should. :) I'm very pleased! Hopefully this post might help others who have the same problem.

    -Iain