Is there any leaking? WP fridges tend to have a leak....model # please the midel # is usually inside the fridge on the top lefthand side.

I did not see the noticeable leak, the model number is ED5GTGXNQ00, so it may be two problem, one is why it will constantly run the motor, another one is why the motor (or other component is so noisy). Thanks.

One more question, if I replace the fan (with motor), the noise may disappear, but it won't fix the potential leak issue, am I right? how to detect the leak, any idea, thanks.

Here is a video that describes how to replace the fan motor:

https://www.youtube.com/watch?v=Uui9QsAYVXQ

The fan cycles on an off as the refrigerator turns on and off as controlled by the thermostat inside the fridge, so if the fan is noisy, that is when you will hear it. The fan cools the compressed refrigerant so it condenses to liquid.

When you replace the fan you'll be able to see if there is ice outside the freezer.