Oven fan is very noisy, rattling, or scraping during operation.

Safety first: Turn off power and allow the oven to cool completely before removing the fan cover.

• Inspect fan blade: Remove the internal fan cover and check for loose screws, bent blades, or debris. Tighten the fan nut if loose (usually reverse thread).
• Clean area: Remove any burnt-on food or foil pieces around the fan.
• Check motor play: Wiggle the fan shaft gently. Excessive play or grinding indicates worn bearings; replace the fan motor.