I mostly drive the car on the highway and I've noticed a whistling sound that comes from under the hood. I can hear it both when I accelerate and decelerate. The dash isn't showing any lights on. What could be making this whistling and buzzing noise?
There is a tensioner pulley that keeps the correct amount of tension on your serpentine belt. When these bearings wear out, they can cause this type of a whistling sound that you describe. This is a quick fix and should not take much time with the proper tools. I would recommend having an expert from YourMechanic come to your home to diagnose and repair the car noise to ensure that this is resolved properly.