Diagnosis
A grinding or rattling noise from the rear wall during convection bake/roast is almost always debris—a piece of foil, a small utensil, or food—hitting the fan blades. The fan motor itself is less likely but possible.
How to Fix It
Inspect and clear the convection fan assembly at the rear of the oven.
- Remove oven racks and the rear interior panel (held by several screws).
- Shine a flashlight and look at the fan blades and the cavity around the motor shaft for any foreign objects.
- Use long-nose pliers or tweezers to carefully remove any debris. Manually spin the fan to check for smooth rotation.
- Replace the panel and test.
If That Didn't Work
If the noise persists with no debris, the fan motor bearings are likely worn out. The motor is serviceable but requires disconnecting wires and removing mounting screws from behind the rear panel. The part number is typically DG94-00645A.
Heads Up
Never cover the oven racks with aluminum foil, especially on the edges, as it can get sucked into the fan. Also, avoid using aerosol oven cleaners near the fan area as they can damage the motor.