What is this noise? it occurs when draking, and slows as the car slows. it does not seem to be a flat tire. My car has less than 45,000 miles. I think I have replaced all the tires once. it is a 2003 Prius (the original, little sedan model)
The first thing that I would check would be the fender liner.
I am always amazed at how many cars I see running around with a drooping fender liner.
Run your hand over the tread surface of the right front tire to see if there is any irregularity. If not move the car forward a foot or so and do the feel test again. If you still cannot find any defect in the tire, rotate the right front tire and wheel to the right rear and see if the noise moves with it.
Get back to us if you have eliminated the tire as the source of the noise.
This is a common symptom of irregular tire wear, but also of an internal failure in the tire, often due to hitting something like a pothole.
Do what Researcher and VDC suggest. If you still cannot find a cause, try jacking up the front wheels (tranny in neutral, parking brake on) and rotating the tires by hand. If you do not hear any suspicious noises, take the car to a shop that does “road force balancing”. A machine that does this rotates the wheel while aimulating road forces by pressing a spinning drum against the tire. That can detect internal tire defects that a regular balancer cannot.
Of course if you feel odd wear patterns as descrbed in Researcher’s post, let us know what the anomolies are and we’ll try to suggest a cause. Well, actually, we’ll probably recommend you visit a chassis shop.
I’ve also seen a torn CV joint boot do this. As it spins, the torn boot flaps against the suspension.