Hard drive clicks are normal when loading and unloading heads. So, if it clicks when it has been idle for a while and then again when you access it that is fine. Though there are ways to reconfigure that.

If it clicks during active access, that does seem to be a problem, and may be lack of power. The power supply is one part of it. The current rating ought to be enough, but is it a decent supply which really provides what it says it does? Then there is the resistance of cables connecting the supply to the RPi and RPi to the hard drive. A cheap high resistance cable can cause undervoltage problems even on the RPi itself with a good power supply.