This bulletin applies to 2015-2019, 2022-2023 Audi A3 and S3 vehicles.
A rattling/grinding noise from the front may be caused by rubbing wear at the brake shield. Check both front brake shields. They should be secured and seated properly.
If damage and/or excessive corrosion is found, replace both shields.
To protect the new brake shields for brake discs against corrosion at the mounting points, wax must be applied all the way around the contact surfaces of the securing bolts before the bolts are installed. Use cavity preservative sealant P/N D 329 215 M1 for this purpose.