Kia service department put the hard sell on me that at 90,000 miles the subframe bushings were worn out, and if I didn’t get them replaced there would be severe consequences such as alignment and suspension problems. They kept coming down on the price but the lowest was $700. There are squeaks and groans while driving but otherwise no symptoms 24,000 miles later. Should I worry?
In my opinion, it’s far more likely your sway bushings and links are the source of the squeaks and groans
These bushings can be easily inspected.
Raise the vehicle on a lift and inspect the rubber bushings for cracking and chunk out. Then with a pry bar place it in between the sub-frame and the uni-body and try moving the sub-frame.
If there’s a problem with the bushings it will be seen.
So get a second opinion from an independent shop.
The visible portion of bushing does crack over time. That does give the impression bushing is “shot” when in fact it may be basically sound. This car may be prone to chronic subframe rust issues. Or not. You can ask parts dept how many they sell each month. None? Or a bunch?
Surface cracks can appear on the surface of bushings, including chassis bushings and suspension bushings. This is natural as the rubber ages and shrinks, and doesn’t mean they are damaged or worn out. A performance test that @Tester recommened to see if there is excessive play is the only real test. If it passes, they are Ok.
You need a second opinion from a good independent mechanic. Forget the dealership because they are just fishing for a boat payment.