2004 Optima Cruise Control and Speedometer issue
I have two issues that may or may not be related.
While driving on the freeway my cruise control will disengage and no longer work. The green light on the button remains lit. A bit of alternating between shutting the cruise off and back on along with tapping the "set" button will sometimes make it engage again but this isn't very often. When cruise is working, it works anywhere from my whole 35 minute drive to class or not at all with no predictable variation. There appears to be no general "cool down time" window for when it stops working and will start to work again either.
I can usually get a sense of when it is about to happen though. I will feel the car attempt to accelerate and the rpms will go up and down right before it shuts off. (On a side note, at 70 mph I'm between 2500-2700 rpms, is this normal to be that high?)
The speedometer issues appears to happen independently, as I am driving it will occasionally drop from 60+ down to 0 for a couple seconds before it shoots back up to the correct speed.