Audi A6 C6 2004 - 2011 - used, experiences, problems

Audi A6 C6

Audi A6 C6

Success with the previous generation Audi A6 also confirmed by another third generation Audi A6 C6. It was introduced in 2004. The exterior and interior design is by a well-known and recognized designer - Walter de Silva. The Audi A6 C6 definitely alludes to its predecessor, but is a bit longer and has a modified front and rear. Inside is a new system Multi Media Interface abbreviated MMI, or - a system for control and entertainment. The 6-speed Tiptronic automatic transmission is also new. 2005 The Audi A6 receives the prestigious World Car of the Year award. There are three body types - sedan, station wagon (Avant from 2005) and Allroad from 2006. After a slight facelift of the 2008 Audi A6 C6, the rear of the car is very similar to the smaller model Audi A4, it also got optional LED headlights.

The Audi A6 is representative of the upper middle class and thus a popular company car. He's a cop Mercedes E Class i Bmw 5 Series .

Audi A6 C6

Audi A6 Allroad Quattro was produced in the period 2006 - 2011. Off-road version of the Audi A6 Avant .It differs from the ordinary Avant with a greater distance from the ground and extended fenders. Unfortunately, the possibilities for driving off-road are much worse than in the previous generation. All cars are equipped with 4 × 4 drive and air suspension. The drive came from 3.2 or 4.2 or 2.7 petrol engines or a 3.0 TDI diesel. In most cases there is a Tiptronic automatic transmission.

Audi A6 Allroad Quattro

Audi A6 Allroad Quattro

Audi S6 and Audi RS6

The Audi S6 looked rather "civilian" from the outside, introduced in 2008. The Audi RS6 is a real monster with very wide fenders. In both versions, the V10 engine - S6 had a 5,2-liter engine with 435 hp, 540 Nm of torque, max. speed: 250 km / h, acceleration from 0 to 100 km / h 5,2 s; RS6 - 5 liters and power of 580 hp, torque 650 Nm, max. speed: 250 km / h, acceleration from 0 to 100 km / h 4,5 s. From the beginning, the RS6 was only available as an Avant, but after a year, the RS 6 sedan was also offered.

COMFORT - Audi A6 C6 

The Audi A6 has a spacious interior, large enough to accommodate five adults. Air conditioning and electronic windows are standard, and the Audi A6 comes with an electronic parking brake that is activated via a switch on the center console. All engines on offer are refined and make a minimal contribution to interior noise. For rear seat passengers it has decent legs and for the head and seats they give a nice balance of soft comfort and good support.

Audi A6 C6

Audi A6 C6

The boot of the Audi A6 offers a decent capacity of 546 liters (sedan), 565 l (Avant up to 1600 l with lowered rear seats) - and is slightly larger than alternatives such as the Bmw 5 Series and Mercedes E-Class. The cargo space itself is wide and fairly easily accessible. The rear seats are divisible by 60/40 and if folded down they can easily carry longer items.

Audi A6 C6 is 4,92 meters long and 1,86 meters wide, it has increased significantly compared to the previous model (4796 x 1810 mm). The height is almost unchanged (1,46 to 1,45 meters), the wheelbase has increased by eight centimeters - in favor of the rear legroom.

Audi A6 C6

Another novelty is the MMI (Multi Media Interface) control system, whose dominant feature is a rotary controller that can control multiple electronic devices. By turning the controller you move through several menus and submenus, the selected function is confirmed by pressing the controller. This interface is also a large black and white or color screen at the top of the center console, where all the commands and functions of the MMI screen are. It should be added that the system is well set up and still works without problems, the problems are solved mainly by upgrading the software.
Multi Media Interface has different variations: from the basic 2G, 2G High, only after the face-lifting of the model available 3G with navigation, DVD and hard drive. You can unlock hidden functions in it through the diagnostic interface.
Note: We advise against attempting to change device settings independently of VAG-COM or VCDS. Without adequate knowledge you can easily lead to a complete blockage of the car.

The Audi A6 C6 has received a lot of criticism on the pre-set trap compared to its competition. Even air suspension does not help with this problem. Driving comfort is also affected by the size of the wheels of the vehicle, of course, care must be taken, 16-inch tires are the best choice.

There is no need to be afraid of any rust problems with the Audi A6. Audi is known for its perfectly protected double galvanized sheet metal, and also the front part of the body (bumpers and hoods) are made of aluminum. Both the front and rear suspension have a complicated multi-link structure, which is actually standard at this time.

The standard Audi A6 equipment is rich, including ESP, ABS, 6 airbags and automatic climate control.

The Audi A6 C6 received 5 stars for the NCAP crash test and 4 stars for child protection.

ENGINE - Audi A6 C6 

From the beginning, all Audi A6 C6 engines meet the Euro 4 norm, and after the facelift the Euro 5 norm. For this reason, the Audi A6 C6 will be remembered as a car with a wide range of engines. The offer of gearboxes consisted of 6 manual, Multitronic and Tiptronic. Gasoline in the first years of production had a problem with the coils. With the TDI engine, the cylinder head may crack, and problems with the turbocharger also occur. You should also pay attention to the hoses of the brake system, and the rubber bearings of the front axle.

The petrol engines of the Audi A6 C6 generate significantly lower maintenance costs. While the base version 2.0 TFSI has a complicated structure, it is a simple 2.4 V6 direct injection engine that you can also add LPG. It is also possible to add gas to the 4.2 V8 engine, but only if there are no FSI marks (the 4.2 FSI is a completely different engine).

Other petrol versions of the Audi A6 have direct fuel injection and LPG will not respond. Note: The 3.2 and 4.2 FSI units have very similar drive chain problems as the 3.0 TDI diesel.

Gasolines have significantly lower maintenance costs. The 2.4 and 4.2 engines use multipoint fuel injection which is fairly easy to maintain. Other engines have direct fuel injection into the combustion chamber and deal with the deposition of carbon deposits on the valves. The 3.2 and 4.2 FSI engines through similar drive chain problems as the 3.0 TDI.

2.0 TFSI - 4-cylinder petrol engine. In other Vw cars it reaches much higher power, with the Audi A6 C6 acting as a base model. Durable, fairly reliable.

 2.4 - The simplest engine, no direct injection, you can install gas without any problems. The engine has a new design, from the previous generation it only partially took over the aluminum engine block. Brand new engine electronics, with a pair of camshafts but operating 30 valves instead of just 24 valves.

2.8 FSI - Very modern direct injection engine, variable valve control and drive chain.

3.0 TFSI - From 2008, under the hood, comes a very powerful six-cylinder direct-injection 3.0 TFSI turbo petrol with a power of 213 KW and 420 Nm of torque, which is available from 2500 to 4850 rpm. With the Audi A6, the dynamics of this engine are really excellent, as is the response to the accelerator pedal.

Audi A6 C6

3.2 FSI - Much more popular with 2,8 ads. Usually in combination with a Tiptronic automatic transmission. Direct injection excludes the installation of auto gas.

4.2 / 4.2 FSI - Audi V8 engines sound great and even better features. Fuel consumption at an acceptable level of 13 - 15 l / 100 km. Gas can be installed in the 4.2 V8 engine, but it is not recommended to install gas in the 4.2 FSI model. The conventional injection motor delivers max. power of 246 Kw, in 2006 it was replaced by an engine of the same displacement, but with direct injection 4.2 TFSI with a power of 257 Kw.

5.2 FSI V10 - a powerful 320 Kw engine for the S6 a version of sports since 2008 and also offered a 5.0 FSI V10 Biturbo for the RS6, which has a power of 426 Kw.

Specifications: Audi A6 C6 (2004-2011) - petrol

Version 2.0 TFSI 2.4 2.8 FSI 2.8 FSI 2.8 FSI
Motor Benz. turbo petrol petrol petrol petrol
 Engine displacement 1984 cm3 2393 cm3 2773 cm3 2773 cm3 2773 cm3
Number of cylinders / valves R4 / 16 V6 / 24 V6 / 24 V6 / 24 V6 / 24
Max. power 170 KS 177 KS 190 KS 210 KS 220 KS
Max. torque 280 Nm 230 Nm 280 Nm 280 Nm 280 Nm
Max. speed 228 km/h 236 km/h 238 km/h 237 km/h 240 km/h
Acceleration 0-100 km / h 8,2 s 9,2 s 8,2 s 8,4 s 7,3 s
Average fuel consumption in l / 100 km 7,5 9,7 8,2 8,8 8,4

Specifications: Audi A6 C6 (2004-2011) - petrol

Version 3.0 TFSI 3.2 FSI 4.2 4.2 FSI
Motor Benz. turbo petrol petrol petrol
Engine displacement 2995 cm3 3123 cm3 4163 cm3 4163 cm3
Number of cylinders / valves V6 / 24 V6 / 24 V8 / 40 V8 / 32
Max. power 290 KS 255 KS 335 KS 350 KS
Max. torque 420 Nm 330 Nm 420 Nm 440 Nm
Max. speed 250 km/h 250 km/h 250 km/h 250 km/h
Acceleration 0-100 km / h 5,9 s 6,9 s 6,5 s 5,9 s
Average fuel consumption in l / 100 km 9,4 9,7 11,7 10,2

2.0 TDI - small "E" means a small sacrifice in favor of ecology: power reduced by 4 hp, has a particulate filter and tires with reduced rolling resistance.

2.0 TDI 140 hp - Turbo diesel engine to be discarded. The 2-liter turbo diesel should only be considered after modernization in 2007, when it was applied to a power system, such as the Common Rail.
2.0 TDI engine of about 140 hp, do not provide enough dynamics (acceleration to 100 km / h in over 10 seconds). The more powerful versions of the 2.0 TDI engine consume about a liter more diesel, but with significantly better performance (9,2 s).
The 2.0 TDI is characterized by questionable reliability and the risk of failure, which increases significantly with the number of kilometers traveled. The oil change interval has a significant impact on reliability, which is sometimes too optimistic 30000 km, so it is recommended to reduce it to a maximum of 15 km. Too much worn out engine oil can affect the turbine and damage the engine mechanics and seal the PD injector. In the event of a dintung failure, the diesel nozzle penetrates the oil and mixes with it. It is clear that in this way the characteristics of the oil worsen and endanger the service life of the engine and accompanying equipment.

2.0 TDI 170 hp - The engine differs significantly from the 140 hp engine, including the presence of non-repairable piezoelectric nozzles.

Significant progress in terms of the reliability of the 2.0 TDI engine has been made with the common rail injection models, which were implemented under the hood of the Audi A6 during 2008 that offers much better performance. The disadvantage of the 2.0 TDI engine is the inability to combine it with 4 × 4 Quattro drive

2.7 TDI - the forerunner of the 3.0 TDI common rail injection system and uses a chain as a drive. To replace the chain, the entire front of the vehicle must be dismantled.
2.7 TDI V6 the turbo diesel uses a chain mounted on the rear of the engine, next to the transmission. Comes with Tiptronic and manual transmission.
3.0 TDI
- in the beginning he had a lot of problems, they were gradually eliminated by Audi engineers. Turbo diesel provides great driving pleasure, but is very expensive to maintain.
Of the facelifts of the Audi A6, the 3.0 TDI V6 s is very interesting, thanks to its 290 hp, it offers sporty performance with acceptable fuel consumption. It makes 4.2 V8 redundant.
Initially problematic, then more and more reliable. It gives a lot of fun to drive and is very expensive to service.

Specifications: Audi A6 C6 (2004-2011) - diesels

Version 2.0 TDI 2.0 TDI 2.0 TDI 2.7 TDI
Motor Turbo diesel Turbo diesel Turbo diesel Turbo diesel
Engine displacement 1968 cm3 1968 cm3 1968 cm3 2698 cm3
Number of cylinders / valves R4 / 16 R4 / 16 R4 / 16 V6 / 24
Max. power 136 KS 140 KS 170 KS 180 KS
Max. torque 320 Nm 320 Nm 350 Nm 380 Nm
Max. speed 208 km/h 208 km/h 225 km/h 228 km/h
Acceleration 0-100 km / h 10,3 s 10,3 s 8,9 s 8,9 s
Average fuel consumption in l / 100 km 6,0 6,3 5,8 7,0

Specifications: Audi A6 C6 (2004-2011) - diesels

Version 2.7 TDI 3.0 TDI 3.0 TDI 3.0 TDI
Motor Turbo diesel Turbo diesel Turbo diesel Turbo diesel
Engine displacement 2698 cm3 2967 cm3 2967 cm3 2967 cm3
Number of cylinders / valves V6 / 24 V6 / 24 V6 / 24 V6 / 24
Max. power 190 KS 225 KS 233 KS 240 KS
Max. torque 400 Nm 450 Nm 450 Nm 500 Nm
Max. speed 232 km/h 243 km/h 247 km/h 250 km/h
Acceleration 0-100 km / h 7,9 s 7,3 s 6,9 s 6,6 s
Average fuel consumption in l / 100 km 7,2 7,9 8,0 7,1

The Audi A6 C6 offers a six-speed manual gearbox, available with 2.4 V6, 3.2 V6, 2.8 TDI, 2.7 TDI and 2.0 TDI V6. Next on the menu is a six-speed automatic Tiptronic, which only comes with Quattro drive, for the 3.2 TDI V6, 3.0 TDI, 4.2 TDI and 3.0 V8 engines. The third offer is closed by an automatic Multitronic transmission, which is significantly improved compared to the previous generation and can transmit up to 330 Nm. The multitronic transmission has a Ramp Start Assist function, preventing reversals when moving on a steep hill. This isn't a bad transmission, but its lifespan is short, so a vehicle with a Multitronic transmission would be properly tested. The start should be smooth, without excessive engine hum and of course the absence of any unnecessary driving sounds.

The oil change interval in the case of the Multitronic transmission is at 60000 km, in the case of the manual and automatic transmission Tiptronic the manufacturer does not require an oil change, but the recommendation is a preventive oil change after 90000 km.

In the Audi A6 Quattro, the powertrain is available in the following versions: 2.8, 3.2, all V8 and V10 diesel 2,7 and 3,0 TDI. The Quattro drive continuously transmits four-wheel drive, but in different proportions. Central Torsen differential torque transfer where required. In addition, the front and rear axles use electronic differential lock.

The Audi A6 C6 trap is durable, but the multi-link system is very expensive to maintain. After driving 150000 km, the front and rear derailleur elements need to be replaced. The weak point is the front wheel bearings.

Audi A6 C6 - model history
2004: End of production of Audi A6 C5, Audi A6 C6 sedan debuts (start of sales in 2005).
2005: Wagon version available (Audia A6 Avant).
2006: Audi A6 Allroad version available (caravan only, pneumatic suspension). The range also complements the V10 engine of the Audi S6.
2007: New 2.8 FSI engine.
2008: The facelift includes front and rear bodywork. In the middle - a new central display, with changes and additions to the formatting indicators, as well as a 3G MMI multimedia controller. Presentation of the strongest Audi A6 RS6.
2010: End of production of Audi RS6.
2011: Audi A6 C7 sedan presentation.

FAULTS - Audi A6 C6

Due to technical progress, the Audi A6 has more or less serious errors. Most of them relate to engines. As in other modern constructions, diesel versions have the most problems.

The Audi A6 C6 is presented as a reliable car, of course, it depends on the mode of use and the mileage. The mileage indicators themselves hide many pitfalls, the mileage returned.

If the chain is traditionally placed in front of the engine, replacement will be relatively simple. But Audi on some engines put a chain on the back of the engine to the gearbox, so to get to the chain the engine must be removed. Some ignore the noise of the chain, claiming that it is normal. Yes - the sound of a chain is normal, but an experienced mechanic will assess whether it has already become too loud. If you skip the chain up to two teeth it can damage the valve. The problem was solved with facelifting in 2008.

Audi A6 C6 petrol engines require lower servicing costs. In the case of FSI motors, there are frequent problems with coils, thermostats, and sometimes with the intake manifold. 2.0 TFSI has complex equipment. The simplest is a 2,4-liter V6 without a direct injection system. The 3.2 FSI and 4.2 FSI engines have problems with the drive chains.

Audi A6 C6 direct injection petrol engines (such as the C6 A6 2.8 FSI, 3.2 FSI and 4.2 FSI) are prone to accumulating soot on the intake valves. Symptoms of carbon deposits on the intake valves include difficulty starting the vehicle (difficult starting), lack of ignition, and engine fault codes related to lack of ignition and poor engine performance. Potentially, deposited soot can damage the catalytic converter or engine turbine.

If the 2.0 and 3.2 liter petrol engines run roughly when starting a cold engine, it will not start and "check engine“Lamp, the problem is with the hydraulic adjustment of the valve, the oil has leaked, the elements of the hydraulic adjustment of the valve must be replaced.

2.4 The petrol engine has problems with the wings in the intake manifold.

The drive chains of the Audi A6 3.2 V6 petrol engine cannot survive the Longlife oil change service mode, it is smarter to switch to an oil change interval of 15000 km.

In the case of the Audi A6 with a 3,2 V6 petrol engine, the sealing plugs in the cylinder head can fall out and cause an oil leak. To solve, old plugs need to be removed and modified plugs installed. Oil leaks can occur on the upper covers of the drive chain, requiring new sealing.

For diesel engines in the Audi A6 with common rail injection (mainly 2.0 TDI and 3.0 TDI), a porous EGR valve cooler occurs, leading to a gradual penetration of coolant into the intake. Ignoring this problem can possibly damage the DPF filter, which is already significantly more expensive to repair. With more mileage, problems with injectors can be expected, which is manifested by increased noise, uneven operation and also a decrease in engine power. In turbochargers, there is sometimes a problem of non-functioning wing regulation.

Audi leaves no doubt as to the durability of the diesel. If you replace what you have to replace (even for big money), you can drive almost indefinitely. It is not uncommon for a 2.0 TDI to cover 500000km as a taxi in 4-5 years and still serve well. However, in light of the upcoming high costs, many people simply sell their cars for little money.

Floating flywheel problems are a common problem with diesels.

The 2.0 TDI engine from the start of production of the Audi A6 C6 has a nozzle pump injection system. These engines do not enjoy a good reputation. They have problems with the EGR valve, fuel pump and oil pump drive that can lead to major engine failures, there are also problems with injectors and floating flywheel. The worst thing that can happen in this unit is the shooting of the engine head, and unfortunately there are no isolated cases. 2008 The 2.0 TDI engine transitions to a more modern common-rail injection system. Note that the 140 hp and 170 hp versions have many structural differences. The most important of these, the more powerful motor uses piezoelectric injectors that cannot be repaired.

Audi A6 2.0 TDI engine vibration symptoms after 50000 km, the problem can be caused by melted injector seals due to the use of the wrong fuel.

The first 2.0 TDI PD 140 hp and PD 170 hp with balance shaft have chains to drive the oil pump and the chain can break or stretch and fall out. It is later switched to a hexagonal shaft as an oil pump drive which is also a problem, the tops of the hexagonal shaft are eaten away. Loss of oil pump drive completely destroys the engine. The oil pump uses a hexagonal shaft as the drive with balance shaft. The life of both solutions is about 100000 to 250000 km. Therefore, it is necessary to replace the oil pump set preventively at least every 100 km.

All VAG models with the 2.0 TDI engine throughout 2005 equipped with Siemens peso injectors are subject to recall, which involves the replacement of all. A short circuit in the injector causes the fuel system to shut down.

Revocation to replace Siemens piezoelectric injectors 2006-2009 2.0 TDI engines. All 2.0 TDI PD motors using piezoelectric Siemens injectors and Siemens ECU motors are affected by this problem.

The first 2.0 TDI (140hp and 170hp) in the said engine mixes oil and fuel due to the failure of the tandem pump.

The Audi A6 2.0 TDI PD engine may have a worn turbocharger problem (higher oil consumption, whistling sound).

Functioning of the DPF filter with the 2.0 TDI engine is not the most reliable and often leads to blockage of the filter, especially when it is often driven on shorter distances. Incomplete regeneration of the DPF filter can cause the oil level to rise.

At higher mileages (about 250000 km or more) there may be problems with the injectors, which is manifested by rough operation of the engine or poor start of a particularly cold engine. Very often there is an increased consumption of diesel fuel. Sometimes there is a problem with a faulty fuel pump (in the tank), which causes problems with starting or the vehicle will not start.

Na 2.7 TDI V6 diesel engines have a problem with the intake air intake valves.

3.0 TDI V6 Quattro water pump failures and also prone to losing coolant when cooling EGR valves.

3.0 TDI with 233 hp. After about 150000 km there are problems with the upper chain tensioner. Audi engineers have put a chain on the side of the gearbox, so to get to the belt it is necessary to remove the engine. Some owners ignore the noise of the chain, claiming that it is normal. In advanced cases, where the noise is too loud, it is possible for the chain to skip a pair of teeth, which can lead to valve damage. After Restiling in 2008, the problem with the tensioner was solved.

A typical problem of all modern diesels, including Audi, is the failure of the turbocharger. There are also problems with the EGR valve, which manifests itself in the form of reduced readiness for the engine to accelerate smoothly.

3.0 TDI engine issue with inlet valves.

In the case of an Audi diesel drive with a manual transmission, there are frequent failures of the floating flywheel. Elimination of the problem requires the replacement of the entire clutch and the flywheel, which represents a significant cost.

In an elevated station wagon (Audi A6 Allroad), there is a failure of the air suspension, which brings high repair costs.

Rapid wear of the rubber elements of the lower trap.

Software upgrades can be a solution to an electronic parking brake problem that refuses to operate. The electronic parking brake can also cause problems due to corrosion of the servomotor cable connections or malfunctions on one of the rear wheels.

Audi A6 caravans can penetrate the washer fluid into the MMI unit located in the trunk.

The airbag can be activated late. In the event of an accident involving the front airbags, it is possible that the airbags are deployed too late. Vehicles with this problem have been recalled and the ECU airbag has been updated. The recall was also due to problems with not activating the air curtains.

The fuel gauge may indicate that the tank is empty, even when the tank is full. Most likely the installation of new software is required.

Frequent failures of ventilation and air conditioning systems. Be sure when you buy that all functions work with ventilation and cooling.

The air conditioning cannot cool down enough and / or the temperature reading is incorrect - this may be due to poor contacts or a faulty outdoor temperature sensor.

The coolant level light on the Audi A6 can illuminate in cold temperatures even when the engine is warm - this may be due to a faulty sensor in the coolant tank.

Remote locking sometimes does not unlock the door due to problems with the door modules - this can be solved by reprogramming the door module.

In the first years of production of the Audi A6, the keyless engine starting system had problems, the Start button did not respond, because the vehicle did not detect the presence in the cabin of the remote control.

The seal of the pollen filter may fail, causing water to leak into the cabin into the legroom.


Excellent finish, rich equipment and the most spacious cabin in the class make it a real pleasure to drive an Audi A6 C6. The interior looks great with no signs of fatigue after two or three hundred thousand miles.

Although the core of the Audi A6 C6's offerings in the secondary market are the diesel versions, compared to the petrol variants. Due to the significantly lower mileage and often (though not always the case) simpler engine structure, gasoline can be an interesting proposition.

Used Audi A6 price - review

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