“gruff” noise when the air conditioner is turned on.
Could be from among the A/C compressor or something in its belt path; the engine compartment cooling fans; an obstruction the hvac air path inside the passenger compartment, blower etc. . The first step is to better ID exactly what part of the car the noise is originating.
Is the sound coming from under the hood area or behind the dash area??
Does it make it with the heat on or just the vent blowing (like on heat but temp set to cool, no AC) or just the AC only??
Does it make the same sound and level of sound with blower motor (inside fan) on low as it does on high??
How long has it been doing this??
Have you had any other work done recently??
How many miles are on the vehicle??
Need as much info as possible…