I bought the car with 44,000 in 2007, and at 85,000 the engine became completely clogged
with oil despite regular oil changes every 3,000-5,000 miles.
The manual recommends changing the oil every 7,500.
A Kia dealership just said to change the oil every 1,000 miles, to clear the clog but that didn't work, and I had to replace the engine.
After the replacement, I've since learned this has been a problem with this particular engine, and Kia has stopped making it.