Mine was making that same type noise. I had to oil the indicator wheel in the extruder. It's the aluminum looking wheel with the print on the front. I could just get some grease inside the center part to stop the noise. I oil all the rails once a week with a light 3 in 1 oil. Hope this helps.

Thanks, I ordered some fine oil for RC brushless motors, hopefully that'll do the trick.

Good suggestion.  I printed those shortly after getting my printer, they work fairly well to solidify everything.

http://www.thingiverse.com/thing:407970

I have been using my 1.0 printer just about every day since I got it at summers end.
The print quality is good, however the printer is much louder than I remember it being.
Its the loudest on the first layer where it prints a little slower compared to other layers.  I hear a rattling/vibration that looks to come from the extruder unit.
Ive made sure all the belts are tight.  It looks like the most rattling/vibration happens on the Y-axis (back and forth) when it is extruding a straight line.  When its loudest I can see the "caution do not touch" sticker on the extruder visibly vibrating.  I suspect its not sliding smoothly on both rails when moving slowly.  This also happens when the printer is filling in a small area on the print.
On small prints, Ive got into the habit of using the slowest speed to avoid the printer shaking itself apart (which will quickly throw the bed off level).

Should I lightly oil the rails or bearings?
Sometimes I will hear a ticking sound coming from the extruder, as though the extruder motor is slipping or jamming, but I do not see any flaws or noticeable errors in the prints.

Thanks!