Recalls: Audi D4 A8
Overview
Manufacturers, or importers, issue recalls for defects or faults which have the potential to cause injury. Generally, manufacturers will inform the original buyers if their vehicle is subject to a recall and of the steps required to remedy the defect or fault. Please note that the recalls below (if any) are for Australian-delivered vehicles only. Furthermore, the number of recalls should not be taken as an indication of a model’s reliability or its safety more generally.
Recalls: Audi D4 A8
Audi D4 A8: glass sunroof could break
In October 2013, a recall was issued for Audi D4 A8 vehicles with glass sliding/tilting sunroofs (PR number 3FE). In these vehicles, an unfavourable stress distribution in the glass roof panel – caused during its production – could cause the glass panel to break unexpectedly, unusually when a door as slammed closed while the vehicle was stationary. The panel consisted of single-layer safety glass which would crumble into small pieces in the event of breakage, posing a slight risk of injury (PRA 2013/13767).
2010-12 Audi D4 A8 4.2 FSI: gearbox leak could cause vehicle to stop
In September 2016, a recall was issued for 2010-12 ‘model year’ Audi D4/4H A8 vehicles that had 4.2-litre FSI V8 engines. In these vehicles, a leak could occur in the solenoid valve which controlled the gearbox heating circuit and – via electrical wiring – the leaking fluid could reach the connector for the engine control unit. If the engine control unit failed, the vehicle may stop running and pose a hazard for other road users (PRA 2016/15364).
2017 model year Audi D4 A8: airbags and pre-tensioners may not deploy as intended
In March 2017, a recall was issued for 2017 model year Audi D4 A8 vehicles. In these vehicles, irregularities in the mix ratio of the igniting agent in some airbag units or seatbelt pre-tensioners could lead to the airbags or belt pre-tensioners not deploying in the event of a collision. As such, the risk of injury for the front occupants of the vehicle was increased. For the VINs of the recalled vehicles, please see PRA 2017/15964.
2010-13 model year Audi 4H A8 and 2012-16 model year Audi 4H A8 Security: loss of power steering
In February 2020, recall campaign 48O8 was issued for 2013-13 model year Audi 4H A8 and 2012-16 model year Audi 4H A8 Security vehicles with V8 or W12 petrol engines. In these vehicles, the hydraulic return hose for the power steering system may leak in the following conditions:
- The power steering was under a high pressure load;
- The steering was at full lock; or
- An uneven road surface caused heavy vibrations.
If the power steering hose leaked, the vehicle may experience reduced or complete power steering failure. Hydraulic fluid may also leak into the engine compartment and it could ignite if it came into contact with hot components. These circumstances increased the likelihood of a collision, thereby increasing the risk of injury to vehicle occupants and other road users. For the VINs of the recalled vehicles, please see PRA 2020/18153.
2012-17 model year Audi D4 A8 4.0 TFSI: engine bay seal could warp or come loose
In December 2020, recall campaign 51G6 was issued for 2012-17 model year Audi D4 A8 vehicles that had 4.0-litre TFSI V8 petrol engines. In these vehicles, the engine bay seal may become warped and come loose. If this occurred, engine vibrations may result in the engine bay seal making contact with hot components in the engine bay. This condition could cause scorching of the seal or other components, resulting in fire or smoking from the engine bay. For the VINs of the recalled vehicles, please see PRA 2020/18651.
2012-17 Audi D4 A8: restricted oil supply to turbos and loss of power
In August 2022, recall campaign 21H7 was issued for 2012-17 Audi D4 A8 vehicles. Due to a manufacturing issue, the oil supply in the oil strainer to the turbochargers may become clogged and affect engine operation. This could cause a loss of power while driving and this condition increased the risk of a collision and injury to vehicle occupants, road users and bystanders. For the VINs of the recalled vehicles, please see REC-005488.
Problems and faults: Audi D4 A8
Overview
This section identifies potential problems, causes and fixes based on the experiences of owners and repairers, online sources and technical service bulletins. This information is provided solely for reference purposes and AustralianCar.Reviews recommends that only properly qualified persons carry out repairs or modifications. Furthermore, the number of items below should not be taken as an indicator of a model’s reliability or the frequency with which they may occur.
To report a problem or fault to the AustralianCar.Reviews team, please use the Contact Us form. Note that AustralianCar.Reviews does not offer advice on automotive problems or disputes; such enquiries will not receive a reply. For vehicles purchased from dealers after 1 January 2011, please see our Australian Consumer Law fact sheet.
Audi A8 V6 diesel engine: NOx emissions “defeat device”
Audi D4 A8 vehicles powered by 3.0-litre diesel V6 engines (engine codes: CDT/CTB) that were available for sale from 2010 have software in the electronic control module (ECM) that can sense – via sensors measuring the position of the steering wheel, vehicle speed, the duration of the engine’s operation and barometric pressure – when the vehicle is undergoing emissions testing. The ECM then operates in a low NOx “temperature conditioning” mode to satisfy emissions standards.
At exactly one second after the completion of the initial phases of the standard test procedure, the software immediately switches to a “normal mode” and changes a number of operating parameters that increased NOx emissions. In other tests where the vehicle did not experience driving conditions similar to the start of the emissions testing procedure, the emissions were higher from the start, consistent with the operation and existence of a “normal mode”.
The software on these vehicles constitutes a “defeat device” since it is an Auxiliary Emissions Control Device (AECD) designed to circumvent emissions testing. Volkswagen has admitted that all its 3.0-litre turbo-diesel engines from ‘model years’ 2009 through to 2016 have defeat devices.
Carbon deposits (build-up) on intake valves
Audi’s naturally aspirated, direct injected petrol engines (such as the D4 A8’s 4.2 FSI) are considered susceptible to accumulating carbon deposits (or build up) on the intake valves. In these direct injection petrol engines, carbon deposits may accumulate on the stem and throat of the intake valve due to:
- the vaporisation of oil which is not trapped by the oil separator; or
- unburned fuel and exhaust gases that escape past the piston rings and enter the crankcase (‘blow-by’).
Since direct injection engines do not spray fuel on the backside of the intake valves, the detergent properties of the fuel cannot remove the carbon build up (as occurs in port injected engines). Symptoms of carbon deposits on the intake valve include difficulty starting the vehicle (hard starting), misfiring and misfire engine codes and reduced engine performance. Potentially, these deposits can result in damage to the catalytic converter and, for turbocharged engines, the turbocharger itself if bits of the deposit break off and enter the exhaust. To remove the carbon deposits, the intake must be removed and the valves cleaned manually. To reduce the incidence of carbon deposits, a common aftermarket measure is the fitment of an oil vapor catch can. The catch can receives dirty air from the crankcase via the Positive Crankcase Ventilation (PCV) valve, filters it and returns it to the intake manifold via the PCV port.
