I have a 3 - 4 year old 250GB WD hard drive that has shown abnormally high temperature readings ever since I bought it. The temperatures were so much higher than expected that I ended up attributing them to a bad sensor. For example, the other drive I have on the my system at the moment is a WD 640GB and it is currently at 40C. While the 250GB drive is at 62C. Typically, when the system boots up the temperature for that drive will quickly clime to 50C - 58C (today's a bit hotter). These drives are right next to each other in the case so that there is no other source of heat that could affect the temperatures.
All in all I never had any problems with that drive (except for the alarming temp readings) but in a recent S.M.A.R.T data check I noticed some CRC errors. These errors are usually attributed to bad cables bad just to be on the safe side I am planning on retiring this drive soon.
In the early days, when the 250GB drive was my main drive I was quite worried so I bought a hard drive cooler for that drive. It manages to to lower the temperature by about 5C. The problem is that it really makes a lot of noise. What I am interested in knowing is if my assumption that it's more than likely a bad sensor is logical so that I can disconnect the hard drive cooler and get some peace and quiet.