Sway bar links most likely. I had the same noise.

It sounds like that because the road vibration makes the link joint rattle.

If you inspect them while installed you won't notice how lose the are. Remove them from the sway bar first and then rock them...if they are loose, bingo

 

Thanks Josuet!
I took a ride with the guy who takes care of my tires today, and the only sound he said he heard sounded like sway bars and that it was "normal". But, it did not make that noise until about a year ago. Are you saying that if I have the sway bars removed, and if they are loose - then have them replaced, or can they be fixed?

 

Not the sway bar, that's a big undertaking. I'm referring to the sway bar links. I piece of metal that connects the sway bar with the shock absorber.

 

If you are not mechanically inclined, I suggest you take it to the dealership to diagnose the issue.



But if comfortable with mechanic repair, remove the front wheel. You'll see the link that connects the sway bar with the shock absorbers.



Place a second jack (assuming you are using the other to lift the car) under the control arm and lift it a little bit to release the pressure of the suspension hanging in the air.

Then remove either terminal of the link. With the other side connected still, articulate the link. It must be hard to move....if it moves easily, that's the problem. You can also inspect the rubber boot at each end of the link, if broken or oily, that's another sign

Links are cheap, about 20 bucks each.

 

Here is an example for an earlier Sorento model. Same logic though

Front Sway Bar Link Replacement 2011 SX AWD

So 100k and some klunks and looseness prompted me to tackle this. The parts are cheap and it's not a complicated procedure but I wanted to point out a few things that could make it easier if you decided to do it. I'm no specialist, and besides my torque wrenches, have basic tools. You'll need...

www.kia-forums.com

 

Thank you so much Josuet, you made my day!

One of the things I have loved about my Sorento is that it is so quiet. The last year with that rattle sound has bugged me!
My tire guy also does suspension work, so I will have him do the work. I'll report back if it solves the issue.

 

Well, I finally got it fixed! I had forgotten that my Sorento has a 5 year warranty, but when I realized it is still under warranty I took it to the dealer. First they did a 4 hour diagnostic, and found nothing. The service advisor said nothing wrong, see you later. I asked to talk with the service manager, and he agreed to look at it more. I left the vehicle there for a week, and he finally figured out that it was the driver's side strut, which needed to be ordered, and finally got replace today! Now I have the quiet ride that I love!

 

Thanks for updating everyone