I agree with Jetmech05, when a servo makes noise, something is probably binding! Look at all parts of the system. Disconnect and inspect the various connections to see if you can pinpoint the cause of this extra effort the servo is being forced to make: servo arm to push rod connection, pushrod to control horn connection, hinges. Disconnect one servo to see if the noise emanates from one servo and not the other. Set-up the plane with the suggested throws stated in the owners manual. Does it still make noise, then? Do all you can to attempt to eliminate the noise. If you are still stuck, ask for help from an experienced person in your club. Noise means the servo is working and is using up your batteries.