Whirlpool refrig ET20DK. Conventional upper freezer type. NO icemaker. Makes heavy buzzing sound when running. The refrig is set into the cabinets rather tightly with zero clearance on the sides, several inches in back and around 3 inches above.
Changed the evap fan several months ago with NO improvement.
I took the rear cardboard noise shield off to view the fan and compressor. Using a mechanic’s statoscope I determined that the noise is definitely the compressor unit. This refrig is maybe 20 yrs old and this noise has only recently worsened to the point that I can’t stand it.

Thanks Rich....No tubing vibration. But this is one of the items that I'm really not capable of replacing myself. I'm thinking it would be cost prohibitive to have someone else do it considering that a new refrig of the same size and quality is less than $1100. What do you think?

That's a good idea. Since the refer is in a tight enclosure of cabinets and gypsum board, I was thinking of sound reduction material on the rear gyp wall and such. Maybe a little applied under the refrig as well. Might get a few more yrs out of the unit.... Thanks.