Appx. 106k miles. My wife’s car so I don’t drive this very often. However, on the last trip, I noticed that it would stay in a particular gear longer than (I think) it should. The RPM’s will go up to maybe 4000 or so and stay there for a while even if I let my foot off the gas before finally kicking into overdrive or the next gear and back to a comfortable cruise. I notice this mostly happened when I was going highway speeds and either passing someone or going up a hill. I can’t think of the last time the transmission fluid was changed, so I’m thinking that may not be a bad place to start…
A proper transmission service is probably the best place to start. If they tell you they want to do a transmission “flush”, go to a different place. You want a proper service, where they drain out the existing fluid, replace the filter, and replace the fluid with exactly the type of fluid suggested by the owner’s manual, and to the correct level.
There’s other possibilities, but that’s where I’d start if it were my car.
I would take it to the dealer and let them do the tranny fluid change. That way you get an oem filter and fluid. I paid $80 for mine at Toyota. I could not do it with oem parts and fluid.
Kia might tell you that the transmission filter is not a serviceable item. Try to find someone who will change it. You’re out of warranty, so Kia might say that the next step is a rebuilt tranny (which it very well might turn out to be).