Rattle in Steering Column - 2016 Sorento LX FWD

[timrice]

Have a 2016 Kia Sorento LX FWD with about 52K that I bought used from a KIA dealer with 42K. The CARFAX on it stated that the dealership had replaced the steering wheel about 50 mi. prior to selling it to me.

I did not notice it during the test drive (city driving / all pavement), but when I got it back home I noticed that on the short gravel road to my house, and even in my gravel driveway, the steering column makes a fairly loud clunking or rattling noise.

When the steering wheel is turned, I'm not feeling any sticking issues or experiencing control issues as have been reported by many (see NHTSA site: https://www.nhtsa.gov/vehicle/2016/KIA/SORENTO/SUV/FWD). There doesn't seem to be any axial play in the steering column, and there's no noise generated simply from turning the wheel through its range of motion.

Only rarely will I hear / feel this on concrete or asphalt pavement. But even on relatively smooth gravel roads, and even at low speeds, the sound and feel of the rattle is fairly intense.

This has me wondering whether it's related to the dealer having replaced the steering wheel (the rattle feels further down). The dealer did not explain why they replaced it--I probably should have asked, but since I didn't notice it on the test drive, I didn't make a point of it.

Just makes me jumpy every time I hear it, because I'm not used to a steering column making rattling noises, and all the worst-case scenarios come to mind.

I know from some YT videos that on some Kia / Hyundai steering systems, there's that little star-shaped rubber / urethane "gear" that sits between the column and the electric power steering motor that gets torn up, but it seems like that always causes noise when the wheel is turned, and I don't have that. I suppose it could be something in my front suspension that is being felt higher up and into the column, too. I've not found any recalls or TSBs that seem relevant.

I'm getting annoyed enough to take it to my mechanic. (Nearest KIA dealer is 75 miles away.) But was wondering if anyone else out there had experienced these symptoms or heard about them.

[timrice]

Point of clarification...
When I said "there's no noise generated simply from turning the wheel through its range of motion," that's true as long as the wheel is turned smoothly as you would in normal use, where the angle of rotation is fairly significant.

However, if the wheel is turned somewhat rapidly back and forth ("jiggled") over a short range of travel, you *can* feel and hear this rattling sound, and it is definitely coming from the steering column. I did this with the car sitting still, in P. Kind of lines up with the observation that gravel roads cause the rattle, because the less-smooth surfaces probably cause very slight angle changes from the tires up through the column as the vehicle goes down the road.

The symptoms do seem similar to the MDPS (Motor-Driven Power Steering) Coupler problems seen in Kia / Hyundai designs where the "soft" star-shaped coupler gets all chewed up and lets the metal parts bang into each other:

https://www.youtube.com/watch?v=rxTcFnykutc
https://www.youtube.com/watch?v=1YS94TPb8Us
https://www.youtube.com/watch?v=Y5BnVlfSVug

I don't know yet whether this coupler (or something similar) was still being used by the time the 2016 Sorentos were built.

[timrice]

Thought I would update this thread with the solution.

It turns out that this particular year / model of Sorento does *not* have that star-shaped coupler in the steering column. My mechanic found 1/8" of play at the end of the intermediate shaft where the splines interface with the rack-and-pinion assembly. The pinch bolt at that end was tight, and I didn't see any obvious wear on the splines on the part he removed. The attached picture illustrates.

He replaced that shaft, and the rattle is gone. MUCH better.
Cost for the genuine Kia part was $250, and $150 labor to install.

Finally, an interesting note the mechanic mentioned. He's worked on a number of the Kia coupler "rattles," and he said the symptoms / sound on my Kia were basically identical to those.