uh how do we know it's not windows/another app trying to do something? does it sound the same as writing/reading or is it a completely new sound? can you make a recording?
i've been using a clicking (head parking) seagate for over 4yrs, it's not dead or dying in my case, it's just a bit unstable & the read speed test is a little more jittery than yours
how are the smart values?