Ge side by side freezer fan

Check to see if fan is loose also check to see if there is ice buildup inside and blade is hitting it

We have summarised all possible problem for this case here to this link
http://www.fixya.com/support/r6008187-side_side_refrigerator_whistling_sound

sounds like the fan bearings are wearing out. this causes imbalance and makes a vibrating howling noise.

Need to unplug the refrigerator and remove the cover inside freezer compartment. Sounds like the evaporator fan is hitting something and we need to resolve this as soon as possible. Thanks Sea Breeze

Replace the fan motor is my guess to cure the noise.

the problem you are having is in the main control board. ge has had a problem with this part causing the fan motor to go into high and low speed which causes the howling noise. unfortunately it is a costly fix, around $125 for the part. if you are savy to changing this part it is a matter of unplgging about 5 connections and replugging them. the new board has an extra set of pin that nothing connects to. READ the instuctions and it is a simple fix, saving about $50-60 in labor costs.

it is most likely the fan bushings that are making the noise. you can try to lube them with a light oil if you want to buy some time. but the fan motor will need to be replaced soon.

this fan is a variable speed and is controlled by a board in the rear of the unit. your bearings maybe going out. The fan will ramp up to speed depending on the call for cooling the Thermistors is asking for

It is very common for the fan inside the freezer to develop a loud noise as it runs. Its in an environment that is hard on them, cold, wet. Its a small and simple motor, and you are right in believing there will be more problem in the future, as the stator is probably touching the housing. It has a sleeve type bearing, and its probably worn a little causing the shaft to wobble. Eventually it will stop completely and the freezer will get warm.