wheel noise

Sonata 2006 GL 4000 miles: I haven't moved the vehicle for about 2 weeks,
during this season of rains.
Now I have a noise every time one of the wheels rotates. Seems to be coming
from the rear ones. Noise frequency accelerates with the rotational speed. I
thought that it could be a brake pad and that it would go away if I drive
and brake. After half an hour of local road driving the noise is still
there.

Any ideas?
FG

 

My first idea is rust on the rotors. The rear doesn't provide that much of
the braking action, so if the rust is the issue, you may need to make
several very hard stops from significant speed to rub it off.

 

'My first idea is rust on the rotors. The rear doesn't provide that much
of the braking action, so if the rust is the issue, you may need to make
several very hard stops from significant speed to rub it off.'

REPLY: Also, several days of continual car useage almost always makes
it go away.

 

That's a long time to sit. Could be flat spots on the tires. Check, air them
up to max (I think the tag on the B pillar states 30psi).

 

Forgot to mention, the brake rotors would have to be severely warped to make
a noise you could hear inside the cabin. Even then, they make a
characteristic "rubbing" sound. You can't usually feel warped rotors until
you apply the brakes and feel it in the pedal.

Flat spots on the tires make a true noise, like whappa-whappa-whappa that
you can hear and feel all the time. It usually goes away after a few days.
Some brands are worse about flat spots than others.

 

Another area to check is the weatherproof sealing
on the door frames, sometimes this pops loose
and you hear road noise from the tires.