I experienced the same problem with my Liana 2007 and sound used to come from compressor once turned on. I showed it to the mechanic and he was able to remove the problem. Problem was related to compressors clutch which was slipping and loose. He was able to remove it from Compressor without removing compressor its self and get it resurfaced on lathe machine and installed it back. Problem was solved and he charged me Rs 500.
I don?t like the ******** that compressor is faulty or that compressor needs to be changed with other one as current one installed is a wrong choice by manufacturer. Had he been so good then would had been working with a renounced manufacture in factory.
Always take the expert opinion from different mechanics before making a game plan.