Used Vehicle Review: Audi A6, 2005-2011

This thread at AudiZine.com is a compilation of a number of posts at the site on the topic of carbon build-up in Audi’s FSI engines. Meanwhile, this thread has ugly photos of carbon buildup in various Audi and Volkswagen TSI motors.

2007 Audi A6 4.2; photos by Chris Chase. Click image to enlarge

The A6’s LED taillight assemblies are source of trouble, triggering intermittent faults warning that a rear taillight and/or turn signal isn’t working.

Failed trunk latches are common. The symptoms are either a trunk that won’t stay shut, or does close, but triggers a “trunk open” warning from the car’s electronics. Lubricating the latch is a short-term fix, but you’ll probably need to replace it eventually.

Air conditioning that won’t blow cold could be caused by a bad connection between a temperature/pressure sensor in the A/C system and the car’s on-board computer.

Here’s a thread at AudiWorld.com about A6s that stall or run rough, along with the appearance of a number of warning lights indicating a fault with the engine’s electronic controls.

A6 owners who have shared their reliability experiences at TrueDelta.com mentioned problems with power steering leaks, power window failures, Bluetooth, as well as a couple mentions of bad fuel pumps. A fuel gauge that reads empty even when there is gas in the tank is commonly caused by a bad wiring connection between the fuel level sending unit and the instrument cluster.

2007 Audi A6 Avant; photo by Peter Bleakney. Click image to enlarge

Beyond the above-noted items, the A6 is also known for problems with many of its electrical accessories and systems.

In crash tests, the Insurance Institute for Highway Safety (IIHS) found little to fault, save for a likelihood of upper leg injury to the driver in its frontal offset impact test. The A6 scores “good” in both that and the side impact test.

The National Highway Traffic Safety Administration (NHTSA) hasn’t crash-tested an A6 since 2002.

Canadian Black Book (CBB) suggests that used A6 values line up pretty closely to those for its competitors from BMW (5 Series) and Mercedes-Benz (E-Class), while comparable cars from Japanese and American makers are less expensive. And, according to CBB, the A6 tends to boast higher resale values, as a percentage of MSRP.

As is the tendency with German sport sedans, the A6 is an appealing car where the driving experience is the priority. The reliability story is the same old song-and-dance: reliability is so-so at best, and replacement parts and repairs are expensive. At least few of the A6’s known problems are serious mechanical flaws, but even that doesn’t fix the fact that too often, a vehicle’s reliability seems inversely proportional to its MSRP. Heed my usual warnings if you do settle on a used A6: have it checked by a trustworthy mechanic before buying, and avoid cars that don’t come with a detailed service history.