my car used to make a distinct whistling sound when the timing chain was old n fucked, its really really annoying, but if i heard it again i could tell you for sure, coz the sound it makes is unlike any other.
is there any way to post a sound file up in here?? if so you could record the sound n the post it up, that would work for diagnosis sound for us. Better yet, if you can just do a vid wif ya phone n then chuck it on ur computer, and then photobucket and then here... and then, and then, and then... and then!! lol