Serviceability Report: Audi A6

Posted 12/10/2012
By Craig Van Batenburg

Audi sales have been doing quite well over the years, and the manufacturer makes some fast, good-looking cars. BMW has real competition. On a recent visit to Germany, I had a chance to get to know Audi better. A part of the Volkswagen group, the brand is well respected as many Audi drivers passed me on the Autobahn at well over 150 mph. I kept to the right as I drove my 1.4 liter rental at a miserly 100-plus.

Once again we will examine a new model that has just been re-engineered. Is fixing and maintaining this vehicle becoming more difficult or were technicians actually considered at the design stage? Let’s find out.

For this comparison we will examine the 2007 A6 Quattro 3.2 liter V6 and the 2012 A6 Quattro 3.0 liter. We will evaluate the progress Audi had made when they redesigned it for 2012. I talked to some Audi technicians, both dealership and independent. Here is the story along with some tech tips.

2007 Audi A6

In model year (MY) 2007 the A6 could have had either a 3.2-liter V6 or a 4.2-liter V8. The base, front-wheel-drive A6 with the V6 engine used a gearless “Multitronic” continuously variable automatic transmission (CVT) that simulated gear changes by switching between predetermined ratios. The gearbox could be “shifted” like a manual transmission in seven stages. The 3.2-liter V6 generated 255 horsepower (hp).

The V6 and V8 models with Audi’s Quattro all-wheel-drive (AWD) system got a six-speed automatic transmission with a “tiptronic” clutchless-manual mode for driver-initiated shifting. Power was transferred to all four wheels using a six-speed conventional automatic transmission manufactured by ZF.

I have reviewed more than 35 cars over the last nine years and only a few have a clean record on recalls. The 2007 A6 is on that list as it has never been recalled. Audi has come a long way from the myth of “unintended acceleration,” which was reported on a segment on CBS’s 60 Minutes in 1986.

Some help here if you have never worked on this car. Keep memory alive when replacing the 12-volt battery or you will be searching for a factory scan tool or a top-of-the-line European scanner. The “Steering Angle Sensor” will require a reset and that is not a big problem if you are properly equipped. You will notice the antilock braking system (ABS) light and/or the electronic stability program (ESP) light illuminated. Identifix has a “Repair-Trac Bulletin,” No. 10851, that will walk you through it. Make sure you use a 12-volt memory saver hooked up to the data link connector (DLC) and not a 9-volt memory saver, as it will not work on Audi vehicles. Computer memory may be erased if you hook up your old 9-volt memory saver.

2012 Audi A6

The new A6 uses a lot of aluminum. In fact, 20 percent of the car is now using this light-weight metal. It has reduced its curb weight by 66 pounds, but it is loaded with creature comforts so it still tips the scales at more than 4,000 pounds.

With the new powertrain came a better fuel economy. The new Audi A6 uses a 3.0-liter, 24-valve V-6 (with direct injection, supercharging, and air-to-water intercooling), and an engine that has been used in other Audis. Rated for 310 horsepower and 325 pound-feet of torque, the supercharged six is paired with ZF’s eight-speed automatic, replacing the previous six-speed. And of course there’s the Quattro all-wheel-drive system, with a torque-sensing center differential that automatically apportions front/rear torque (normally 40/60, variable between 15/85 and 70/30) as well as an electronically controlled limited-slip differential at each axle.

The supercharged V6 moves two-plus tons to 60 mph in 5.4 seconds, covers the quarter-mile in 13.9 seconds at 102 mph, and tops out at 129 mph when the governor says that’s enough. No governor in Germany so it is good for 160 mph. As this car is so new it has no known problems and service looks similar to the 2007 model. Three hundred and seventeen A6s built in April and May of 2011 were recalled for defective side curtain airbags. The stitching was not done properly so owners had to bring them back for new airbags. After that, so far so good. At $50,000-plus, Audi owners expect a lot.

Open the hood and it is not very scary. Most components look like you can get to them. Oil filter on top, coil-on-plug is staring at you. After removing the usual plastic covers (it is a V6) it may still be cramped at times, depending on what you are going after.

What is Multitronic vs. Tiptronic?

Multitronic is a chain-driven CVT with two pulleys. It acts as automatic but can also be shifted manually. It has been problematic. Technicians who work on these CVT transmissions tell me they often get complaints of “hesitation on acceleration” after a rebuild. Adaptation or a “learning process” has to be performed or the clutch values from the computer are not recognized. Another problem after a rebuild is when the car comes to a stop, the car shakes and hesitates and seems not to respond to the accelerator pedal.

The problem only exists in the “D” or “S” mode. In selector position “R” the car won’t move at all. If this happens, try turning the ignition off and on again. The car may reset itself and all will be OK. This may be a one-time issue that will not come back.

The common problem with the CVT transmission is a failure in the valve body, (hydraulic control unit). Dirty ATF with particles in the oil may cause a sticky valve body. Instead of a smooth movement of the reaction valve, high pressure rises up on the sticky reaction valve and forces the valve to close with a bang shortly before the car comes to a stop. It is also supposed to shift into first gear, but it doesn’t. Customers really don’t like this.

Check the transmission fluid, and if you have metal particles in the oil the size of one millimeter or more, it is time to replace the transmission. If the oil has a burnt smell, you might get away with a new filter and oil. Multi­tronic transmissions are not popular as most people buy the Tiptronic with AWD.

The Tiptronic is a multi-speed conventional transmission that has paddle shifters. Nothing special to learn here, just make sure the fluid is changed when needed. This is a good solid unit.

Preventive maintenance

Some Audi authorities suggest that you don’t need to change your Audi’s automatic transmission fluid. This is illogical. An Audi automatic transmission has hundreds of moving components, such as needle bearings, pressure pumps, clutch packs, servo pistons and seals. These internal components mesh with one another, begin to wear, and create fine metallic particles that contaminate the Audi automatic transmission fluid (ATF).

Over time, the Audi automatic transmission fluid and the paper filament transmission filter become contaminated with these particles. New transmission fluid is nearly clear in color. If you’ve ever seen the dark color of old transmission fluid, suggest changing the Audi automatic transmission fluid and filter. The pan and filter are easy to get to.

Just like hybrid and electric car service, many shops just stay away. When it comes to Audi, that seems to also be the case. A good scan tool is required to test the oil change intervals and do minor work so an investment up front of proper tooling is required if you want this work in your shop.

2007 A6 summary

Audi should be on your list of vehicles to service for a few reasons. They are not perfect cars so you can make money fixing them. The owners are upper middle class and many will pay you well for good service. Once you get over the learning curve most technicians tell me they are “just another car.”

2012 A6 summary

The new A6 is a best-seller for Audi so there will be many to service as the years go by and they age. Information is easy to access on the Internet and once you gear up for Audi you have done most of what is needed to service Volkswagen.

A special thanks to Aaron Hollingshead and Chris Walberg from Parker Audi in Little Rock, Ark., for answering many questions while I visited their great city.

Craig Van Batenburg, AAM, is a master hybrid technician. He was the owner and lead technician for more than 25 years at his own shop that specialized in Honda and Toyota vehicles. Van Batenburg was president of ASA-Massachusetts from 1993 to 1996. He owns Automo­tive Career Development Center (ACDC), which he founded in 1998. He develops technical classes for those who require updating their knowledge in hybrid and electric cars. His customers include the U.S. Army, U.S. Marines, Delphi, Midtronics, John Deere, Porsche of America and BG Products. You can reach Van Batenburg at craig@auto-careers.org.