Diagnosis
The auger motor is straining against a physical obstruction. For new grills, this is almost always caused by foreign material in the pellet hopper.
How to Fix It
Immediately turn the grill off and unplug it. Empty the entire pellet hopper. Visually and manually inspect every handful of pellets for manufacturing debris like plastic wrap, wood splinters, or metal fragments. Remove any foreign objects. Refill with clean, high-quality pellets.
If That Didn't Work
The noise may indicate a misaligned auger. This requires inspecting the auger tube assembly. If debris is ruled out, contact Traeger support. Do not continue to run a grinding auger.
Heads Up
Always inspect pellets before loading. Bagged pellets can contain packaging debris. The auger motor is not designed to shear through solid objects and can be damaged.