Does it make the noise under the hood area?
In the dash area?
Does the a/c still function?
If under hood area it could be a compressor clutch that is faulty...
I would need more info to further diagnose.
〉 Answered on Aug 7th, 2007 by Amanda J. Pierce, MBA "AJ", Certified Mechanic, Project Coordinator; Primavera Scheduler at VIGOR Alaska Industrial Shipyard & BizzM3ch Solutions