I have a 95 ford mustang 3.8 liter v6... With engine problems

Question

Sitting idle with the air off the car will rev to and stay constantly between 2000-2500 rpms, and the sound from the engine I would have to compare it to "uhgg" sound that you would hear from a zombie in a horror movie, but only constant!!!! When I turn the air on The sound will go away and the reving will die down, and fluctuate from 1500-2500rpms please help asap!!!

Answer 1

It could be one of the drive belts.

Answer 2

could be anything but start by checking for a vacuum leak, the easiest way to do this is buy a can of berrymans carb cleaner, open the hood and squirt it around the rubber hoses, when the engine revs more, check that hose, it could be, off,cracked or broke. if all thats ok, it might be a bad idle solenoid, go buy the Chiltons book at autozone or whereever and look it up, it's pretty easy to check. hope this helps