I have an IBM ST2000NM0011, and it makes a thumping sound whenever I'm reading or writing to it. I got it from a friend, so I'm not sure when it started making the sound or if it's bad. Is the hard drive failing, or is it normal?
Hard drives of that generation should not make thumping sounds. The exception would be if they are improperly mounted.
That drive, a Constellation ES SATA drive, was likely manufactured in the early 2010's.
Here is the reference manual for it, from Seagate.
It's likely failing. I would not recommend using it for any important data.