I have another small issue that I need help with diagnosing, ever since I bought that ( 5 years ago ) the cooling fan always seems to be on and loud, when you press the gas pedal it is even louder. So the research I have found points to the fan clutch. Most people recommend try spinning the fan and see how easily it turns, I did that and it doesn't continue to spin other than maybe a 1/4 turn.
Any other suggestions. my friends Xterra even does this, I cant see this being normal