My bass is f***ing me off (never knew it didnt censor it XD)

[antipodean]

That rattle could be the truss rod, this happened to my fender jazz when I played the D on the 2nd string. So I picked off the 5th fret dot, drilled a hole in the fret board and squirted in some of that expanding space filler builders use. The rattle's gone, but I also lost the dot to put back on. Yep, I'm retarded. My advice is to take it to a proper techie. (BTW, the truss rod is the bit of metal in the middle of the neck that you adjust to straighten the neck)