Tire or Bearing noise? LR tire/wheel

Hello all,
I have searched this forum for all items relating to wheel bearing and tire noises. I have found some good info but wanted to get some new opinions about how well insulated the rear area is on these cars.
I have a 1999 GL 3.8 II with 93xxx miles. At all speeds there is a low rumbling sound that seems to be focused at the left rear wheel area. As I am driving I can hear it quite well, however, from the passenger seat it is much less noticable. The sound is kind of like going over expansion joints on the road, one right after the other. The sound gets faster as I speed up but not really any louder. I would say just more pronounced due to speed since it is nearly continuous, but still like expansion joint noise. I have had the wheel bearings checked at a local place. They did an alignment and replaced the 2 lower ball joints. They also found that the LR wheel had a pretty good size dent on the inside so they replaced that wheel as well. All of this did not really change the sound it makes. I was sure hoping it was that dented wheel! Now I am suspecting that perhaps the tire was damaged when the wheel was hit. Would a damaged tire show up during a wheel balance?
But what I really want to know, do these cars have higher than average tire noise? And if not, what are the chances that wheel bearing can start making a low rumbling sound before they are loose enough to cause movement in the wheel itself by grabbing the top and bottom and rocking.
Sorry for the long post but really want to put forth as much detail as possible.
Thanks!

Wheel bearings can definitely be making noise before showing any axial runout. Although you could have tire noise, too. Feel the tire with your hand for irregularities, scalloping, unevenness, etc. Get the rear end off the ground and spin the tire - listen for noise near the hub. Spin the other side and compare.

Typically a wheel bearing would either only make noise when turning a certain direction, or at least the noise would be more pronounced somehow by taking a turn in one direction or the other (depends on which bearing is bad).

One way to determine if a tire is at fault, or at least find out if a wheel/tire assembly is causing a problem is to take the car to an establishment that uses a Hunter Road-Force balancing machine.
http://www.gsp9700.com/pub/features/how.cfm
If you use their locating feature, you can find an establishment near you (hopefully).

It almost sounds like you might have a bad wheel bearing on the rear perhaps. There isnt much you can do in the way of "freebies" to see what the problem is. Unless you wanted to swap right and left rear wheel bearings to see if the noise moves to the other side. Or swap wheel/tire assemblies to see if the noise changes at all.

It was the tires! I "rotated" front to rear/rear to front on the dirvers side and the noise moved to the front! In fact it was worse than ever. I looked the tire over and could not see or feel any unusual cups or bumps. Could have been out of round but instead of trying to continue the troubleshooting, I replaced all 4 tires. Ride and handling have improved greatly.
I think it is important to note that even when tires look and feel ok, they can still have problems, hard spots, etc. that cause noise and even driveability issues. :2cents:

One of them could have also failed internally, like one of the belts if they happen to have had steel belts in them, which a lot of tires do.

Glad you got it fixed though.

At all speeds there is a low rumbling sound that seems to be focused at the left rear wheel area. As I am driving I can hear it quite well, however, from the passenger seat it is much less noticable. The sound is kind of like going over expansion joints on the road, one right after the other. The sound gets faster as I speed up but not really any louder. I would say just more pronounced due to speed since it is nearly continuous, but still like expansion joint noise.

my Dad's 1999 Intrigue had this problem in the left rear original also. It's a constant thumping noise that can really get into your head. My car had it to a much lesser degree.

A good set of quality touring tires really helps the Intrigue ride quality and cuts down on noise also.