Wheel/Brake Noise?

[sixcrows]

When driving next to buildings or on tight streets with the window open, I notice a distinct "metal" sounding noise coming from my wheels (at least it sounds like it's coming from the wheels). It almost sounds like the brakes are lightly engaged and are constantly scraping. The car is not slowing or pulling to one side or the other. When I lightly depress the brakes, the sound seems to lessen or stop.

I made an appointment at my smart dealership, and they agreed to look at the car after my work day ended. They took a look at it while I waited. They told me that the brakes are NOT scraping, although they were able to hear the noise as well. The technician said he took out another smart and it also had the noise. I didn't think to ask if I could drive another one at the time. Duh.

So, apparently the car is fine. However, now that the weather is warm here in the Northeast, I drive with the windows open all the time. Every time I pass a car parked on the left, I can hear the metallic sound.

Do any of you experience the sound? Before I bring it back for another look by the smart center, I want to hear others' reflections.

Thanks,
Walt

[SMART]

Very odd... I noticed this exact same thing today... I was wandering if it's something from the brakes?

[xcrew229x]

A small screeching noise perhaps? I'd bet it's brake pads scraping on a slight rust on the very edge of the rotors. Just a guess......

[WikkidSMAHT]

Walt, I just logged on to the forum to research this exact same issue. You did a great job of describing the noise. I noticed it in a drive-thru this afternoon. Sounded like the front wheels to me. I also noticed a change in pitch as I turned the wheels from side to side while moving slowly. Mine is just a few days old, so I"m probably paying too much attention.

You saved me a trip to the dealer!

[sixcrows]

Originally Posted by WikkidSMAHT

Walt, I just logged on to the forum to research this exact same issue. You did a great job of describing the noise. I noticed it in a drive-thru this afternoon. Sounded like the front wheels to me. I also noticed a change in pitch as I turned the wheels from side to side while moving slowly. Mine is just a few days old, so I"m probably paying too much attention.

You saved me a trip to the dealer!

Thank goodness at least two others have heard this noise. Can it be just US? It's not a good noise. Very harsh sound.

Anybody else have any idea where this noise is coming from?

[Old smart]

I'm not sure where I came across the information (Evilution, smartManiacs?), but it said that rust on the edge of the rotor can cause that sort of noise. There is info in Evilution about rear brake noise due to rust and brake dust within the drum. But it seems odd that a new vehicle would have either of those issues so soon.

Caliper pistons not retracting??

[xcrew229x]

Backing plate on the front rotors is very close to the rotor, and covers the back of it entirely except for where the caliper is. Wouldn't take much for a small rock to get lodged between it and the rotor, or much to bend the backing plate to where it hits the rotor. Also, anyone buying different lug bolts, check for rear clearance with the spindle. Current bolts are about 24mm long (shank), and just for reference I screwed one in w/o the wheel on, and it hits the spindle when rotated about 12 o'clock. Backed out one turn it clears. Just for info.......

[Karl Roth]

Drum brakes have springs that retract the friction material (shoes) away from the drums. Disk pads do not they reley on the minute irregularities in the disk to retract them. the calipers if not "frozen" or unable to retract should allow spacing that will be close to silent for most of us. A persistant harsh noise is sign of a problem you should get checked at a reliable shop... hope that helps
karl

[oldbike]

Disc brake pads are always in very slight contact with the rotor. The heat of the pads changes the pitch slightly. Driving along a wall amplifies the noise. Just the fact that you are sitting closer to the wheel than in most cars may account for some of it as well. Try another of your cars and I think you will note it as well.