nay transformer can develop a noise from the transformer metal plates if there even a little loose, the looseness causes the plates to vibrate to the ac 60 hz rate of the ac input power, that won't hurt anything, sometime you can stop the vibration but is not a issue and not to be concerned about! you could take the top of the transformer off and use an insulted probe and push the metal brackets to find the noise might come and go away, but I would not recommend it if you don't know what your doing you could get shocked or damage your transformer.
Alan
