Audi A8 — service and repair in Espoo

Audi presented the first A8 in 1994 as the successor to the Audi V8. The model became an important technological step for the brand: the production A8 received the aluminium Audi Space Frame body structure — ASF. Production of the first A8 began in Neckarsulm in 1994.

The first generation also formed the basis for the unique Audi A8 6.0 W12. In 2001 a production A8 appeared with a six-litre twelve-cylinder W12 engine, all-wheel drive and an automatic gearbox.

Audi presented the fourth generation D5 in 2017. It received a completely new electronic architecture, a 48-volt system, modern air suspension and a large number of assistants.

Main generations:

The first-generation A8 is already a classic car today. It can be found with petrol V6 and V8 engines, diesel TDI units, a W12 on the later top version, automatic gearboxes and quattro.

The main technical feature of the D2 is the aluminium Audi Space Frame body. Aluminium corrosion differs from ordinary steel-body rust, and incorrect body repairs can create separate problems.

The age of the car means that servicing should especially include checks of:

The Audi A8 D3 is significantly more complex than the first generation. On the used market you will find 3.0 TDI, 4.0 TDI, 4.2 TDI, petrol V6 and V8, W12, Tiptronic, quattro, air suspension and MMI.

Today most D3 cars have significant age and mileage. Buying a cheap A8 D3 without prior diagnostics can lead to repairs whose cost is comparable to the price of the car itself.

During diagnostics it is especially worth checking:

The D4 generation appeared in 2010. It received more modern engines, electronic systems and additional equipment.

The most common versions include 3.0 TDI, 4.2 TDI, 3.0 TFSI, 4.0 TFSI, W12, Tiptronic and quattro. For the D4 the following are especially relevant:

D5 is the fourth generation of the A8. The car became significantly more electronic. Audi uses it as the brand’s technological flagship. After the facelift the model was offered with 3.0 TFSI, 3.0 TDI, 4.0 TFSI and plug-in hybrid TFSI e.

The A8 50 TDI quattro uses a 3.0 TDI with 210 kW and 600 Nm of torque. The A8 55 TFSI quattro has a 3.0 TFSI with 250 kW. The more powerful A8 60 TFSI quattro is fitted with a 4.0 TFSI V8.

On the D5 diagnostics should pay particular attention to:

The Audi A8 requires a different servicing approach from more compact Audi models. High mass, high power and a large amount of extra equipment place increased load on the brakes, suspension, cooling system, gearbox, batteries and tyres.

On an A8 it is especially unwise to postpone a minor fault. Because of the car’s complexity, one problem can over time create load on other systems. Items worth checking regularly include:

Across different A8 generations V6 and V8 TFSI engines have been used. Modern versions include 3.0 TFSI and 4.0 TFSI.

On the updated D5 the 3.0 TFSI develops 250 kW, and the 4.0 TFSI in the A8 60 TFSI develops 338 kW. The V8 also uses a cylinder on demand system that can temporarily deactivate four cylinders under light load.

When servicing TFSI engines it is worth monitoring engine oil, spark plugs, coils, turbocharging, the cooling system, crankcase ventilation, the chain drive and the condition of the engine mounts. Diagnostics are needed if:

The 3.0 TFSI is widely used on D4 and D5. It is a powerful engine, but at high mileage attention should be paid to the cooling system, pump and thermostat, chain drive, ignition system, turbocharging or compressor system on earlier generations, and crankcase ventilation.

If the engine starts to run unevenly, expensive components should not be replaced immediately. Faults, corrections and actual parameters are checked first.

The 4.0 TFSI V8 is used on powerful A8 and S8 models. The engine has a complex turbocharging system and high thermal load.

On such engines preventive diagnostics are especially justified because of the high cost of components. It is particularly important to monitor:

Large diesel A8 cars are well suited to long-distance driving. Across different generations 3.0 TDI, 4.0 TDI and 4.2 TDI have been used.

On the D5 the A8 50 TDI uses a 3.0 TDI V6 with 210 kW and 600 Nm. When servicing the diesel it is worth checking:

The DPF particulate filter gradually accumulates soot and ash. On normal highway journeys regeneration usually takes place without problems. If a large diesel A8 is used mainly in the city, conditions for regeneration become less favourable.

Before cleaning it is necessary to check soot and ash quantity, differential pressure, temperature sensors, EGR and engine operation. Signs of a problem include:

Diesel A8 cars use an exhaust gas recirculation system. Over time soot and deposits can accumulate in it.

If the coolant level also starts to drop, the EGR cooler should be checked. Possible symptoms include:

Modern diesel A8 cars are fitted with SCR. An AdBlue fault is not necessarily related only to a lack of fluid.

If a countdown to an engine start inhibit appears, diagnostics should be carried out before zero mileage is reached. Possible causes include:

Most modern A8 engines have a chain drive. On many V6 and V8 engines the chain mechanism has a complex design and may be located on the transmission side.

Not every short noise means that a full chain replacement is required. Diagnostic values and the condition of the system must be checked. Reasons for inspection include:

The classic torque-converter Tiptronic automatic is especially characteristic of the Audi A8. On the D5 plug-in hybrid the electric motor is also integrated into the eight-speed Tiptronic.

On a high-mileage car the gearbox service history is very important. Diagnostics also check mounts, driveshafts, the propshaft, electronic control and oil temperature. Inspection is needed if:

Quattro all-wheel drive is one of the core features of the A8. Most powerful versions have permanent all-wheel drive.

For quattro it is especially important to use tyres of the same size and similar wear. Servicing must take into account central torque distribution, the front and rear differentials, the propshaft, CV joints and transmission fluids.

Diagnostics are needed if:

The A8 has a complex all-wheel-drive transmission. A similar hum can come from a hub bearing or tyres, so the source must first be localised.

Signs of a possible fault include:

The D5 was also produced as the plug-in hybrid A8 60 TFSI e quattro. The powertrain combines a 3.0 TFSI, an electric motor, a high-voltage battery, an eight-speed Tiptronic and quattro.

After the facelift the battery has a usable capacity of about 14.4 kWh, and the combined system output reaches 330 kW in Audi’s published technical materials.

Servicing must take into account both the combustion engine and the high-voltage system. Work on high-voltage components requires appropriate qualifications.

The cause is not necessarily in the high-voltage battery. The charge point, cable, charge port, port lock, 12V battery, charging electronics, high-voltage system and stored faults all need to be checked.

Diagnostics are needed if:

The D5 uses a 48-volt electrical architecture on the relevant powertrains. It enables mild-hybrid functions and powers certain high-power vehicle systems.

For example, Predictive Active Suspension uses electric actuators at each wheel that operate from the 48-volt system.

If numerous electrical faults appear, the following need to be checked:

Adaptive air suspension is one of the characteristic systems of the A8. On the updated D5 adaptive air suspension with electronically controlled dampers is standard equipment.

The main components are air springs, the compressor, the valve block, lines and level sensors. If the car gradually lowers, the leak must be found first. Replacing the compressor alone will not fix a sealing problem.

Signs of a fault include:

A complex active suspension is available on the D5. The system uses electromechanical actuators at each wheel and can raise or lower the body individually. Audi states that it can actively change the position of each wheel and uses the 48-volt electrical system.

It works together with a camera that analyses the road ahead. Faults in such a system require specialised diagnostics.

Possible symptoms include:

The A8 D5 can be equipped with all-wheel steering. At low speeds the rear wheels help reduce the turning circle, and at high speed they improve stability.

After suspension or steering repairs it is especially important to carry out geometry and the necessary calibrations correctly.

Even without an active system the A8 design is quite complex. The car’s high mass places load on control arms, bushes, ball joints, anti-roll bar links and hub bearings.

Before wheel alignment, play must first be ruled out. Inspection is needed for:

The high mass of the A8 and large wheels place high load on hub bearings. The main symptom is a hum that increases with speed.

On quattro a similar sound can come from differentials or the propshaft. The source must therefore be identified accurately before replacement.

The Audi A8 is a heavy and powerful car. The condition of the braking system is especially important. In Finland road salt can accelerate disc corrosion, seized guides and damage to brake mechanisms.

Especially high-performance brakes are also available for the S8, including optional carbon-ceramic discs on certain versions. Diagnostics are needed if:

The Audi A8 has a large number of electrical consumers. Even after the engine is switched off, numerous comfort and safety units still need power.

Diagnostics of many random faults should therefore often start with a power-supply check. A weak battery can cause:

The A8 is a flagship model, so the amount of electronic equipment is especially large. Depending on generation the car may have several screens, a digital instrument cluster, navigation, Rear Seat Entertainment, Bang & Olufsen, seat massage, electric blinds and electric drives for almost all adjustments.

A problem in one unit sometimes affects several systems. Diagnostics are needed if:

A modern A8 may have adaptive cruise control, Audi pre sense, Lane Assist, blind-spot monitoring, 360° cameras, night vision and parking assistants.

The systems depend on precise sensor calibration. After windscreen replacement, body repair or significant suspension work, cameras and radars may need recalibration.

The A8 may have a four-zone climate system. On TFSI e the air conditioning is also linked to the thermal management of high-voltage components. Audi notes the use of a heat pump and joint control of several cooling circuits on the hybrid version.

The cause may be refrigerant, the compressor, valves, sensors or flap actuators. Inspection is needed if:

The A8 L has an extended wheelbase and is oriented even more strongly towards rear-passenger comfort. Technically the main systems are close to the standard A8, but the car has a longer body, increased mass and additional rear-cabin equipment.

It is especially worth checking:

The S8 is the sporty version of the A8. It combines an executive body with a powerful V8, quattro and more sporty suspension settings. On the D5 S8 dynamic rear-wheel steering is also standard.

Before purchase it is also worth checking whether the car has been software-modified. When servicing, the following are especially important:

Historically the A8 is distinguished by extensive use of aluminium. The first generation became a landmark production car with an aluminium Audi Space Frame.

The D5 already uses a multi-material structure. Audi states that a significant part of the body consists of aluminium, but high-strength steel, magnesium and carbon fibre are also used.

Body repairs on an A8 therefore require the correct technology. After a serious accident it is especially important to check the quality of previous repairs.

A pre-purchase inspection of an Audi A8 is especially useful because the cost of complex repairs can be high.

For TFSI e the high-voltage battery, charging system, hybrid mode and stored high-voltage faults are also checked.

On the A8 the used-market price can fall much faster than the value of its components, so a low purchase price does not mean cheap servicing. It is recommended to check:

At Volkkarihuolto Espoo you can book:

Book diagnostics if:

Need Audi A8 repair or maintenance? Contact Volkkarihuolto Espoo at Ruukinmestarintie 7, 02330 Espoo.

We can diagnose petrol TFSI and diesel TDI engines, Tiptronic, quattro, DPF, EGR, AdBlue, turbocharging, timing chain drive, brakes, air and active suspension, 12V/48V systems, MMI and other electrical equipment.

When servicing an Audi A8 it is especially important to consider the generation and equipment. An older A8 D3 3.0 TDI, an A8 D4 V8, a modern D5 50 TDI and a plug-in hybrid 60 TFSI e have completely different systems and require different approaches to diagnostics and preventive maintenance.