Engine Noise in Car: A6 4B (1999) Fix (Solution)

Loud engine noise in the passenger compartment.

Cause:
Improper installation or the use of a non-foamed bellows (seal between the steering gear and the front panel) can cause noise to be transmitted into the passenger compartment.
Missing sealing plug on the front wall (behind the fuel filter).
Insufficient insulation (absorption) on the firewall on the engine compartment side leads to significant noise transmission.

Solution:
1. Install the foamed bellows, part number 4D0 422 326 (ensure proper installation).

2. Check if a sealing plug is installed on the front panel. If not, install sealing plug No. 8D0 803 583 D.

Furthermore, a visual inspection of the entire front panel sealing should be performed to ensure that no engine noise is entering the passenger compartment due to missing or improperly installed plugs.

The insulation material with part number 4B0 863 815 B is not recommended for retrofitting, as the steering gear needs to be removed during installation.