I have two things wrong with my 2000 Ford Focus with 83,000 miles. One noise sounds like crickets int the engine when the car is warming up. Then stops when it is fully warm The other is that it is struggling to idle. It does not stull but is is just rough. What are these issues and if needs to be fixed how much is reasonable?
Often the sound of crickets chirping when warming up coupled with difficulty idling is somewhere amount the items being turned by the serpentine belt. You could have a failing alternator bearing, perhaps even something else not turning readily that’s loading down the belt, perhaps even loading down the crank.
The only way to find this one is with your head under the hood. Remove the belt if you’re up to it and see if everything is turning readily.
NOTE: look carefully for signs of coolant leakage also. A failing water pump is not out of the range of possibilities.