The Audi A6 is a series of executive cars manufactured by Volkswagen-owned manufacturer Audi AG, starting with a mid-size car in 1994 and continuing to the present with a hybrid electric car. In 1999, a semi-offroad model was released as the Audi Allroad quattro, but it wasn't until 2005 that Audi redesigned and renamed the vehicle
Audi A6 quattro. It had a few off-road styling cues including larger bumpers and sills and had remarkable sporty performance and operating convenience. It was plagued, however, with a few faults that prompted some recalls. Here are some of them.
Problems with the stitching process on the curtain airbag's seams have been reported in late 2011. Manufacturing faults like these pose a great risk to passenger safety in the event of a crash. A head curtain airbag may not even deploy during a crash because of this. Audi recalled around 300 A6 quattros and replaced the curtain airbags affected free of charge.
A defective fuel tank rollover valve can cause serious problems to the vehicle. A significant number of Audi A6 quattro units are affected by this problem, attributed to the material the fuel tank rollover valve is made from. The aging of the plastic material and the stress from the aluminum ventilation line may lead to cracking of the connection nipple. Ultimately, the damaged nipple could leak fuel, which could then lead to fire.
Audi recalled a number of A6 quattros in 2011 and reinforced the connection nipple on the rollover valve. Cracked connection nipples were repaired as necessary.
Some A6 quattros are observed to produce an electrical short that could potentially start a fire. Apparently, the A6 was designed with a weak knee bolster. When the driver's knees push against it, the wiring harness located under the dashboard may be disturbed and an electrical short can occur. The NHTSA, after observing this seemingly minor flaw, suggested that dealers install a protective covering on the knee bolster. Also, they need to check both the wiring harness and the felt protector on the left side of the dashboard for damage and replace either or both them if necessary.