2001 Jeep Cherokee A/C

I've got a weird problem, and am hoping someone can help. My a/c compressor would make almost like a "rattle" sound when it was turned to a/c or defrost. Had the compressor changed, and the new one worked well for about a week. Now this one makes the rattle sound. The orifice tube was changed also. Any thoughts? Thanks to any and all that can help