Light Metallic Scraping Noise From Wheels – Speed Related

[daehttub2000]

I’ve noticed that my 2002 WRX has developed a light metallic scraping noise that is changes in direct relation to the speed of the wheel rotation. I’ve noticed it when I drive slowly down an alley with my windows open and the radio off, There also seems to be a bit of a light metallic rattle when I’m stopped and idling (a bit early for the heat shield to fail?)

 

A little background: My WRX is parked most of the time (summer, fair weather car <30,000 miles). I’ve been quarreling with the dealer over the infamous cold clutch chatter, which is very intermittent with my car. Maybe 25% of the time when it’s cold I get that weird jerky clutch thing. I honestly don't beat on the car (no drop clutch starts -- O.K. maybe a couple of times...)

 

Do I have a sticky/rusted brake caliper? Is my clutch chatter getting worse? Does Subaru make flimsy heat shields? Do I take it in to the Subie dealer to get hosed by the service department for a non-issue?

 

Any help or advice is appreciated.

 

Thanks!

 

P.S. I do remember people talking about "normal" brake caliper noise depending upon temp/humidity, etc. but I don't remember if was valid or just bunk.

[SuBrat84]

Sounds like your brakes are getting low.. probably the rear pads but you should change all four. As for the rattling it kind of sounds like you may have gotten your catalytic converter or reasonator pipe hot enough to get some stuff starting to go loose in there. That kind of noise needs to be tracked down better to determine where it is coming from.

[OB99W]

I’ve noticed that my 2002 WRX has developed a light metallic scraping noise that is changes in direct relation to the speed of the wheel rotation. I’ve noticed it when I drive slowly down an alley with my windows open and the radio off,[...]

Do I have a sticky/rusted brake caliper? [...]

The brake rotors rust very easily, and if the car is driven infrequently rust can build up a bit between uses, especially under humid conditions. You could have a sticking caliper, but even if the calipers are releasing correctly, there isn't much clearance between the rotor and pads. You can hear the pads scraping rust on the rotor surface, especially when driving down an alley or near a fence, wall, etc.

 

If the brake lining is worn sufficiently, you might hear the wear indicator scraping. Hopefully, you're not hearing a pad's metal backing plate running on a rotor, but with under 30,000 miles that's unlikely unless brake usage has been very hard or a caliper is really stuck.

[nipper]

The brake rotors rust very easily, and if the car is driven infrequently rust can build up a bit between uses, especially under humid conditions. You could have a sticking caliper, but even if the calipers are releasing correctly, there isn't much clearance between the rotor and pads. You can hear the pads scraping rust on the rotor surface, especially when driving down an alley or near a fence, wall, etc.

 

If the brake lining is worn sufficiently, you might hear the wear indicator scraping. Hopefully, you're not hearing a pad's metal backing plate running on a rotor, but with under 30,000 miles that's unlikely unless brake usage has been very hard or a caliper is really stuck.

 

what he said

 

nipper

[GaryW]

I had a similar thing happen to my 2000 Forester.

 

My conclusion was that some corrosion on the wheel/brakes caused the cyclic scraping sound. Boy was it scary.. it sounds nasty. But after driving for a couple miles, the sound went away and has not returned.

 

There were a few rather moist/humid/rainy days and the car sat in the driveway for 3 days or so. I think it was just enough to corrode somewhat.

 

On the other hand, be cautious if you hear such noise. I had a sears auto center rotate my tires once. They incorrectly mounted my front right tire.. it was not on flush.. and also made a nasty scraping noise. I knew darn well what it was as I had just left the place when the sound started. Never did I go back.

 

Oh.. I should also mention they denied that was the problem. After 'looking' at the car they said there was nothing wrong. Interestingly.. the sound stopped after leaving the place.. and I watched what they did carefully. They remounted the very same tire.

 

I no longer trust sears, nor many of the 'speedy' type oil places. I have had too many amateur mechanics there that just do things 'fast' without caring about the quality of their work. Many busted splashguard fasteners, oil and ATF fluid overfills, I had enough. The convenience wasn't worth the pain.

 

*now that I have strayed from the topic.. i'll stop*

 

-Gary

[nipper]

I had a similar thing happen to my 2000 Forester.

 

My conclusion was that some corrosion on the wheel/brakes caused the cyclic scraping sound. Boy was it scary.. it sounds nasty. But after driving for a couple miles, the sound went away and has not returned.

 

There were a few rather moist/humid/rainy days and the car sat in the driveway for 3 days or so. I think it was just enough to corrode somewhat.

 

On the other hand, be cautious if you hear such noise. I had a sears auto center rotate my tires once. They incorrectly mounted my front right tire.. it was not on flush.. and also made a nasty scraping noise. I knew darn well what it was as I had just left the place when the sound started. Never did I go back.

 

 

Sears in general is a very very bad p[lace

Oh.. I should also mention they denied that was the problem. After 'looking' at the car they said there was nothing wrong. Interestingly.. the sound stopped after leaving the place.. and I watched what they did carefully. They remounted the very same tire.

 

I no longer trust sears, nor many of the 'speedy' type oil places. I have had too many amateur mechanics there that just do things 'fast' without caring about the quality of their work. Many busted splashguard fasteners, oil and ATF fluid overfills, I had enough. The convenience wasn't worth the pain.

 

*now that I have strayed from the topic.. i'll stop*

 

-Gary

 

Sears in general is a very very bad place for auto repairs, they got in a lot of trouble here in NY a few years ago.

 

nipper

[daehttub2000]

Thanks for all your feedback. It’s been very helpful and informative. My rotors appear to be clean with no rust but I haven't taken the wheels off to take a really close look. The car is always garaged and I don’t drive it in the rain unless I get stuck on a long road trip. However, I do remember that there sometimes is a noticeable hesitation and a loud snap (like something getting unstuck) when the car finally starts moving when I back my car out of the garage after it’s been sitting for a long time (first drive of the spring, etc.).

It’s almost time for my 30,000-mile service so I think I might just take it in and get everything taken care of. Now there’s another question. I know the 30,000-mile service is a bit of a boondoggle for the dealer but it’s a convenient one-stop service for busy/lazy owners. What do you think? I do have an extended warranty so I think I’m required to do it but otherwise would you pay for the service?

As far as the discussion on the quick-lube and other service places, caveat emptor. I’ve learned to double-check everything after going. Years ago, I used to bring my own synthetic oil before all the places carried it. One place actually took my synthetic oil, didn’t change it, and charged me. I only found out at my next fill-up when I routinely checked my oil and found it black and dirty. I’ve had everything from improperly installed brake pads, oil spilled all over the engine (what a smell!), over/under fills, leaking oil pan plugs (goofed up gaskets), savaged aluminum rims after tire changes, etc. etc. I think everybody has a few horror stories… One of the nice things of being a regular at your pricey local Subie dealer is that they make more of an attempt to get things right.

[OB99W]

[...]However, I do remember that there sometimes is a noticeable hesitation and a loud snap (like something getting unstuck) when the car finally starts moving when I back my car out of the garage after it’s been sitting for a long time (first drive of the spring, etc.).[...]

That's probably the parking brake taking its time releasing. You might want to verify that the cable isn't hanging up and causing the p-brake to drag.