Engine noise when A/C or heat is off

2000 grand prix gtp seems to have a problem with warm weather and not using the AC. Last summer it started having like a ting ting metal sound whenever the AC was off, turn it on and as soon as the compressor kicks in it was quiet. come winter didnt matter was quiet all the time, now its getting warm out again and the same problem, no heat or AC and it makes the noise turn it on and it is quiet again.
So my guess is something in the clutch on the compressor is shot, but i do not know much about working on the AC compressor at all, is it possible to replace the clutch or pulley or bearing or whatever it might be on there without having to rip out the entire compressor and drain the AC system?

Any suggestions on what it might be and how to fix it would be great, its one of those annoying things that doesnt effect operation of the car but is something i want to address finally.
Thanks for the help

your diagnosis of the A/C compressor is correct. As far as what might need to be replaced is a little harder. It could be the clutch and pulley bearing, or it could be the front compressor bearing. Normally, a front compressor bearing failure will also cause a refrigerant leak, but not always so inspection is your best bet before buying parts.

ok thanks,
as far as diagnosing the problem further, how can i proceed to do that. i dont believe it is leaking any refrigerant, i checked it last summer and the pressure was good and didnt need any added so if that helps narrow it down?

if you take the belt off and just the compressor pulley has lateral play (meaning it wobbles or you can move it in and out independent of the front clutch plate), then you most likely need just the pulley (it comes with the bearing) and clutch plate. They wear as a set and should be replaced as such. If the entire front of the compressor moves together, then the compressor shaft bearing is shot and it would be more cost and time effective to replace the entire compressor.

OK thank you
i will have to look at it this weekend weather permitting of course.
Do you recomend any specific part number or manufacturer for these parts or is any aftermarket generic autozone vip type part good, assuming they even carry it