That certainly doesn’t sound good. The servo sounds like it’s on its way out. These do fail over time but are straightforward to replace.
If yours is a recent purchase, please contact us by email or through our contact form and we can send you a replacement. Otherwise, we do sell replacements both directly ( http://emsl.us/903 ) and through resellers ( https://www.robotshop.com/uk/evil-mad-scientist-replacement-servo-motor-axidraw.html ).
One additional thing to check is that the vertical slide does fall raise and fall freely when the servo motor lifts it. If it is having difficulty sliding, that will reduce the servo lifetime, so please check on that.
Now, is that grinding noise from the servo or from the plotter, when moving in X and Y? If it’s the latter, then try disconnecting the servo (at the connector on the left side of the machine), and try a plot that way. If a servo is failing, it can draw too much power, which can affect XY movement. If you are still having some kind of difficulty with XY movement, please write to technical support directly (again by email or our contact from); we’ll have some additional things for you to check.