sir_nasty...thanks for the warning. I'll try to be careful when I do this.

 

You should pick up a can of belt dressing from Autozone, walmart, etc and spray it on one belt at a time. If the sound goes away, then the belt is a likely culprit. Tightening that belt might eliminate the noise.

 

timing belt was done but what about the water pump, tensioner, tensioner pulley and idler pulley?(all located under the timing belt)

if the noise goes away when you shift into the neutral i'd be weary of blaming something on the timing side and move toward the (crappy) transmission side. of course, it's much easier to say what you think the noise is when you are in front of the car listening to it.

however, another very common failure is the alternator. it whines and moans when it goes bad, it sounds like a UFO type sound(think xfiles, hehe). probably bad diodes.