The Audi A6 C7 is a comfortable executive car, but early models with 2.0 TFSI and TDI engines in particular suffer from some annoying teething troubles. Choose a car built after 2016 to largely avoid oil consumption and timing chain issues, and always check for sweating rear lights and the air suspension. If you do buy an early A6, a thorough inspection is essential.
Why model year 2016 is considered a milestone
The Audi A6 C7 came onto the market in 2011 and was facelifted in 2014. Yet the biggest technical issues only really start to decline from model year 2016. Early 2.0 TFSI engines, especially the Gen 2 version, regularly suffer from timing chain tensioners that do not last long enough. This can lead to serious engine damage if the chain jumps or slips.
Oil consumption on 1.8 and 2.0 TFSI engines is also a well-known concern on examples built before 2016. Some owners report having to top up as much as one and a half litres of oil between services. This is often caused by poorly functioning piston rings or by a design in which the engine structurally uses more oil. After 2016, specialists see these complaints much less frequently.
For the TDI versions, the main issues involve the particulate filter, EGR system and other emission components. These remain vulnerable even on later years, but the risk of chain problems is smaller than with the petrol engines. If you choose a diesel, check in particular whether the car has mainly done motorway mileage. That helps to keep the particulate filter healthy.
Risks when buying a used 2.0 TFSI
The 2.0 TFSI is attractive thanks to its lower running costs and smooth drivetrain. However, buyers need to be alert to a few known weaknesses. The timing chain tensioner in the Gen 2 engine is fragile and can fail without clear prior warning. A cold start is therefore the best indicator: if you hear a rattling noise just after starting, the chain or tensioner is often already worn.
When viewing a car, ask about oil consumption between services. A healthy 2.0 TFSI uses virtually no oil, but early engines can structurally consume too much oil due to design choices. If the seller says they regularly top up the oil, you should be cautious. Always have the engine checked for fault codes before buying. Misfires and sensor faults often point to deeper issues with the drivetrain or ignition.
Buyers who still opt for an early model are wise to consider only examples with a complete and well-documented service history. A car that has recently had timing chain work or a tensioner replacement is usually more interesting than a cheaper example with no proof of major maintenance.
Recognise symptoms during a test drive
- Rattling at cold start points to a chain or tensioner problem
- Blue-grey exhaust smoke indicates oil consumption
- Erratic idle speed may point to misfires or coil pack faults
- A warning light or engine management light is a reason to carry out an in-depth diagnostic scan
Known weak points of the TDI engines
The TDI engines in the A6 C7 are popular with business drivers thanks to their fuel economy and low CO₂ emissions (carbon dioxide). However, the 2.0 TDI and 3.0 TDI each have their own points to watch. In the case of the 2.0 TDI, the biggest risk is the diesel particulate filter. Short journeys and lots of urban driving cause the filter to clog up. If the car regularly goes into limp mode or you get warnings about the emission system, there is often a clogged or defective particulate filter (DPF, diesel particulate filter).
The EGR system is also sensitive to contamination and can cause irregular engine behaviour. When buying used, have the car scanned to see whether there have been previous emission-related fault codes. If these have been cleared without proper repair, they often come back. A car with mainly motorway mileage is therefore often a better choice than one that has only done short trips.
The 3.0 TDI is regarded as stronger and more reliable than the 2.0 TDI. The engine itself lasts longer, but the surrounding emission systems remain vulnerable. Anyone who covers high mileages and regularly drives long distances can get many years of use from a 3.0 TDI, provided the maintenance is in order and DPF regeneration functions normally.
Checklist for buying used
Before you buy an A6 C7, a thorough inspection is required. Do not rely solely on a tidy appearance or smart-looking bodywork. Technical problems often only become noticeable after some time, but with the right checks you can avoid expensive surprises.
Always check these points
- Start the engine from cold and listen for rattling noises or irregular idle speed
- Ask about oil consumption between services, especially on TFSI engines
- Check the rear lights for condensation or sweating, especially on post-2014 cars
- Test the air suspension in all settings and listen for compressor noises
- Have the car scanned for fault codes in the engine, emission and driver assistance systems
- Ask for the service history and invoices for major services or repairs
- Check whether the particulate filter has been replaced or cleaned on high-mileage diesels
Pay extra attention to the air suspension if the car sinks quickly after switching off. This points to leaking air springs or a worn compressor. Replacement costs can quickly run into the thousands of euros. Sweating rear lights are mainly a problem on facelifted models from 2014 onwards. This may appear to be purely cosmetic, but it can lead to failure of the rear light units and tarnishing of the reflector from the inside.
‘ In that case, a fully documented service history is not optional, but essential. ’
Which model year is the best choice
If you want to buy an Audi A6 C7, ideally look for an example from 2016 or newer. From that year onwards, most of the timing chain and oil consumption teething problems on TFSI engines were resolved. The electronics and assistance systems are also more stable from 2016. The facelifted models from 2014 look more modern, but from a technical point of view 2016 and later remain the safest choice.
If you nevertheless choose an earlier A6, always have a specialist take a look. In that case, a fully documented service history is not optional, but essential. Cars that have recently had major work on the chain, turbo or emission systems are often more attractive than a cheaper example with no proof. With early models you should always budget for additional maintenance costs in the coming years.
On the Carnews website you will find more information about car problems with various makes and models. Discover which choices other car enthusiasts make and stay informed about known issues with popular used cars.
Frequently asked questions
The most common and serious reliability problems on the A6 C7 TFSI are timing chain and chain tensioner issues (with a risk of severe engine damage) and increased oil consumption. On the TDIs – especially the 2.0 TDI – it is mainly failures in the emission systems such as the particulate filter (DPF) and EGR that lead to expensive repairs. The 3.0 TDI engine itself is regarded as relatively robust, but even there the DPF/EGR and related emission components remain a sensitive point. On all versions, the service history plays a crucial role in the car’s real-world reliability.
For the 2.0 TFSI, you should roughly allow anything from several hundred euros for diagnosis/minor work to well over a thousand euros if the timing chain has to be completely replaced in the event of chain and oil consumption problems. On the TDIs, the DPF and EGR are the well-known cost drivers: regeneration or cleaning usually costs a few hundred euros, while replacing a DPF or carrying out extensive EGR repairs can quickly head towards (and sometimes past) a thousand euros. The 3.0 TDI itself is generally more robust, but if work has to be carried out on the emission system, costs rise to similarly high levels. Naturally, the actual amounts depend heavily on the type of workshop (dealer vs specialist), the parts used (OEM vs aftermarket) and the exact nature of the damage.
With TFSI engines, pay specific attention to chain rattling on a cold start, fault codes relating to the timing system and increased oil consumption (blue smoke, frequent top-ups). On TDIs, check the condition of the DPF and EGR: look for warning lights, regeneration problems, hesitation or lack of power, and (black/grey) smoke under acceleration. Always have the car fully scanned for engine and emission faults and check whether timing chain/DPF/EGR work has demonstrably been carried out. Also look for a fully completed service history with a recent major service and correct oil and filter use.
For both TFSI and TDI engines, it is sensible to invest preventively in proper and timely maintenance, including regular oil changes with the correct specification and the preventive inspection and, if necessary, replacement of the timing chain (and tensioner) on the TFSI. Before purchase, always have the car fully scanned and mechanically inspected, with special attention to timing chain noises (TFSI) and the condition and operating history of the DPF and EGR (TDI). For a TDI, consider a software update or cleaning of the DPF/EGR if there are already signs of clogging or faults, and avoid use patterns consisting only of short journeys. Ideally, choose an example with demonstrably recent major servicing and any timing chain, DPF or EGR work already carried out to limit future failures.
The known problems (such as timing chain and oil consumption issues on the TFSI and DPF/EGR problems on the TDI) can significantly increase the total cost of ownership due to expensive repairs, additional maintenance and possible downtime. Uncertainty surrounding these risks depresses residual values, because buyers price in a risk premium or prefer to choose an alternative. An example with demonstrably resolved timing chain, DPF or EGR issues and a complete service history retains its value relatively better and has more predictable costs. Cars without a clear history or with major jobs looming will depreciate faster and are more difficult to sell.