Audi A3 8L MJ 1999: Rattling/Humming Noise (Solution)

A rattling, clattering, or humming noise coming from the front left wheel well, occurring within the RPM range of 1500-3000.

Cause.
Starting with model year '99, a new cold air intake system was implemented, drawing air in through the front left wheel well. Due to this modification, vibrations may occur between the wheel well and the fender liner, potentially causing the fender liner to flutter.


Solution:
Cut a 20x50 mm piece from the foam rubber with the number 443 201 365 B and glue it to the inside of the wheel arch liner.