My suspicion is the fan clutch for me. I've heard similar sounds from some different trucks with that exact problem. I'm hoping it is because replacing the fan clutch compared to the cooling fan is about a 500 dollar difference on just part alone. Thanks for the info @AxelR. If you've got any more details that would be great. Although this guy had his chevy trailblazer do the same thing after he replaced the fan clutch and water pump.