Jeep engine sounds like AC/heat is on

jeep
cherokee

#1

I have a 2000 Jeep Cherokee Sport with 70K miles. Runs fine with one (possibly?) big exception: For the past few months the car sounds and feels like the heat or AC is on, even though it’s not…makes the same loud noise it does when either heat or AC is cycling on and off. The engine is not idling any higher than normal, at least judging by the RPM gauge. Any thoughts? Thanks.