I think grinding noise from AC compressor has been mentioned here before..
but mine is weird.

it only gives me the noise at idle,
once I get it runnin it never gives me the noise.

my compressor is like 3month new and the ac works perfectly,
just recently this noise started..

is this like lack of oil inside or something like that?

any tip for solution or diagnosis is appreciated

 

Too many questions need answered. Did you change only the compressor?
How much oil did you put back in when you recharged it?
Did you use a vacuum pump and evacuate it when you charged it?
Does it only make the noise when the clutch is engaged?
What was your reason for changing out the old compressor?
Was it a R-12 system when you pulled it down?

 

Very common on these cars. Worse on the V-belt ones. It's the pulsations of the individual cylinders in the compressor.

Probably not anything to worry about.

I'm guessing this is the first time you've ever had working AC in this car?

 

sorry for not putting much detail.

when I got my tax return money, I took my car to a shop
to replace my ac compressor, and retrofitted to r134 caz my old one was not working.
so I didnt do the job, i dont know how much oil was put in etc..

compressor and clutch, and high pressure switch is all new
and ac does blow cold air.

and yeah ur right.. I never really worked or studied about the ac or heating system. I guess it is nothing to worry about, I mean, everything do work fine thanks though