About this model
The Audi A6 C7 was built from 2011 to 2018 and is the fourth generation of the A6, riding on the MLB platform. In BiH it shows up regularly as the go-to executive used car for drivers in their later years, usually with the 2.0 TDI engine in either the Limousine or Avant body. As a premium segment car, the A6 demands premium maintenance, a fact many new owners only discover after their first major repair bill. The EA189 and EA288 diesel mechanicals are generally sound, but the surrounding electronics and mechatronics fail more often than on the A4 or Passat of the same era. In our workshop we see the A6 C7 almost every week, mostly with the same list of faults we'll walk through below.
Engines and variants
In BiH this model is most commonly available with the following engines.
CGLC / CGLD / CMGB (EA189, 2011-2014) - common-rail 2.0 TDI without AdBlue, 130 or 177 hp, with DPF and EGR. Most prone to timing chain issues, EGR cooler failure and early DPF problems; no NOx sensors so diagnostics are a bit simpler. This is the version we see most often in BiH, since they're imports from Germany and Austria, mostly the 177 hp variant with quattro drive. Parts are reasonably priced and most independent shops can service them without software headaches.
CSUA / CSUB (EA288, 2014-2018) - common-rail 2.0 TDI with AdBlue/SCR, 150 or 190 hp, updated EGR and cooler. The timing chain is more reliable than on the EA189, but NOx sensors, the AdBlue pump and the SCR system carry most of the faults. This is the version chosen by drivers who want the newer look and slightly better fuel consumption, but they need to budget for AdBlue upkeep and pricier sensors. Diagnostics require newer equipment (ODIS) to work properly with the SCR system.
CNHA / CVPA (EA288 BiTurbo, 230 hp) - twin-turbo 2.0 TDI version in higher trims, quattro and S-tronic only. The extra small turbo and more complex control system make it more prone to small turbo and bypass valve issues; the rest is similar to CSUA. This one is rare in BiH and needs an owner who understands maintenance costs more than a regular 2.0 TDI. If you do go for this variant, insist on a complete service history.
Reliability and reputation on the BiH market
The Audi A6 C7 with the 2.0 TDI can easily clear 300,000 km if it has been serviced regularly by a serious mechanic. The problem isn't the engine itself, which is proven and durable, but the surrounding systems: the timing chain on the EA189, AdBlue and NOx sensors on the EA288, the multitronic CVT and the surrounding electronics. Owners coming from an A4 B8 or Passat B7 with the same engine are often surprised by the cost when something fails on the A6, because parts are more expensive and the work is more demanding. In BiH we see plenty of high-mileage examples (200,000+) from Germany and Austria, and they're usually good cars if they were serviced within the Audi network. Avant versions with quattro are more sought after than the Limousine, but they bring extra costs around the rear differential and Haldex system. The model's reputation on our market is solid but realistic - those who know what they're buying and what to expect will be happy; those looking for a "German car without costs" will be disappointed after the first major repair.
Common faults we see
From the workshop floor, here's what most often comes in for repair on this model.
1. Timing chain - stretching and tensioner
Symptom: Rattle from the gearbox side on a cold start, fault code P0016 (crank-cam correlation), rough idle, loss of power.
On CGLC and CGLD engines (2011-2014, EA189) the timing chain sits on the flywheel side and over time the hydraulic tensioner gives up, the chain stretches and the cam-to-crank timing shifts. It most often shows up past 180,000 km, but we've seen it earlier on cars with short trips and skipped oil intervals.
Advice: If you hear a rattle from the back of the engine at start-up, don't put it off. The chain, guides and tensioner get replaced as a kit, along with the cover gasket. Never just the tensioner.
2. DPF filter - clogging and regenerations
Symptom: DPF warning light, limp mode, increased fuel consumption, thick smoke under acceleration, oil on the dipstick rising and smelling of diesel.
The car is mostly driven around town in Banja Luka - short trips, cold engine, regenerations that never finish. The oil gets diluted with diesel, the DPF fills with ash. Particularly troublesome on the CGLC and early CSUA because they don't have AdBlue, so all NOx control runs through the EGR and DPF.
Advice: Before replacing the DPF, always diagnose first - it's often the differential pressure sensor or failed regenerations. Chemical DPF cleaning and adaptations can extend its life by years.
3. EGR valve and EGR cooler
Symptom: Loss of power, thick black smoke, coolant smell from the exhaust, dropping coolant level with no visible leak, fault P0401/P0402.
The EGR cooler on the 2.0 TDI is known for leaking coolant internally into the intake manifold. The car slowly "drinks" coolant for months before the owner notices. The EGR valve sticks with soot deposits and doesn't open or close properly.
Advice: When coolant is dropping with no visible leak, look at the EGR cooler first. If the valve is just stuck, chemical cleaning and adaptation often fixes the problem without replacement.
4. NOx sensors (post-2014, CSUA/CNHA with AdBlue)
Symptom: Check engine, faults P229F/P2BAD/P11CB, "engine restart denied in X km" warning on the DIS, power restriction.
Models with AdBlue (from late 2014) have two NOx sensors (before and after the SCR catalyst). The sensors are expensive and typically fail between 120,000 and 180,000 km. Audi even covered this component under extended warranty in some markets, but not in BiH.
Advice: Don't ignore the "restart denied" warning - the car really won't start after a certain number of attempts. We fit OEM, VDO or Bosch NOx sensors; we don't recommend the cheap Chinese ones.
5. Multitronic CVT (mechatronic failure)
Symptom: Jerking from a standstill, loss of drive, "PRNDS" flashing on the cluster, faults in transmission memory, limp mode.
The front-wheel-drive A6 C7 is mostly fitted with the Multitronic CVT (0AW). The mechatronics and the chain link belt are the weak points, especially if the oil wasn't serviced every 60,000 km. Quattro versions get the S-tronic DSG, which is more reliable but also needs oil services. On the early cars (2011-2012) we saw slightly more failures than on later years.
Advice: Change the multitronic oil and filter every 50,000-70,000 km, depending on driving style, no excuses. If it jerks on take-off, an adaptation and oil change may be enough - it isn't always a write-off. Come in for diagnostics before it fails completely.
6. Turbo (VGT geometry) - sticking vanes
Symptom: Weak pull in the mid-range, smoke on acceleration, whistling, fault P0299 (underboost) or P2563.
The variable geometry turbo gets gummed up with soot over time, the vanes don't change angle and the car loses power. Often comes paired with a clogged DPF and dirty EGR. On the motorway at 130 km/h you notice it suddenly - the shove just isn't there anymore.
Advice: Before replacing the turbo, chemically clean the VGT mechanism and check the vacuum actuator. In half the cases the problem isn't the turbo itself but the mechanism around it.
7. Water pump and thermostat
Symptom: Coolant leak under the front of the engine, overheating on the motorway, cold engine in winter (thermostat stuck open), pump bearing noise.
The plastic thermostat housing and the water pump with its plastic impeller are a known weak spot on EA189/EA288 engines. They typically fail between 120,000-200,000 km, depending on driving conditions and coolant quality. The housing cracks along the seam, coolant leaks out.
Advice: When the water pump is being replaced, do the thermostat and housing in the same service - they're almost guaranteed to be next. Use only G13 coolant, the purple one.
8. Electronic parking brake (EPB) - actuators
Symptom: "Parking brake fault" message, brake won't release or engage, clicking from the motor at the rear wheel, uneven pad wear.
The A6 C7 has electronic parking brakes with a small motor on each rear caliper. The motors typically fail after 150,000-200,000 km, especially if the car sits for long periods or is driven in winter road salt. Diagnostics are mandatory, you can't service them "blind".
Advice: Every brake pad change must use diagnostics (VCDS/ODIS) to wind back the actuators, never by hand. If you skip this, the actuator can be damaged and costs three times more than the pads.
Audi A6 C7 burning coolant - EGR cooler
If your coolant level slowly drops with no wet trace under the car, the prime suspect is the EGR cooler. Coolant leaks inside the intake manifold and gets burnt in the engine, so the loss only shows on the dipstick, and you may notice a characteristic sweet smell from the exhaust. The other possible cause is the thermostat housing and water pump mentioned earlier. In both cases a cooling system pressure test reveals the leak and diagnostics confirm which part is at fault. Don't keep topping up for years without checking - once coolant enters the cylinder, the engine damage costs far more than an EGR cooler replacement.
Service and maintenance
The timing chain (CGLC/CGLD) isn't replaced on a mileage schedule but by symptom - we look at it preventively in the 130,000-170,000 km range, depending on how the engine has been looked after. Change the engine oil every 12,000-15,000 km, never the 30,000 km "longlife" interval Audi suggests; BiH conditions (short trips, dust, low-temperature driving) don't allow it. Oil spec is VW 507.00, 5W-30. Multitronic CVT oil and filter every 50,000-70,000 km, S-tronic DSG every 60,000-80,000 km, depending on load. Top up AdBlue as needed (the light comes on about 2,400 km before the car shuts down). Clean the DPF chemically as a preventive measure between 180,000-220,000 km if the car does a lot of city driving.
Which oil for the Audi A6 C7 2.0 TDI
For all 2.0 TDI variants (CGLC, CGLD, CSUA, CSUB, CNHA) the same oil spec applies: VW 507.00, 5W-30 viscosity. This is a low-SAPS oil required for engines with a DPF, because regular oil quickly clogs the filter with ash. We use Castrol Edge, Liqui Moly Top Tec 4200, Motul Specific 504/507 and similar brands that carry the 507.00 approval printed on the bottle. The service fill is about 4.3 litres including a filter change. Important: regardless of what the service book says about a 30,000 km "longlife" interval, in BiH conditions we shorten it to 12,000-15,000 km, because short city trips dilute the oil with diesel and degrade the additives before the mileage is reached.
Owner tips
- Before buying a specific example: use the VIN to pull the full history of the car via carVertical. The international registers usually show real odometer readings by date, recorded accidents, the number of previous owners and theft or total-loss indicators. We consider it mandatory before buying any used A6 C7, especially the German and Austrian imports that land here. When paying for the report, use the code GAGA for a 20% discount.
- Change 5W-30 VW 507.00 oil every 12,000-15,000 km, not on Audi's "longlife" interval - BiH conditions don't allow it.
- On CGLC/CGLD engines, listen for a rattle on cold start - it's the first sign of a stretched timing chain; come in immediately, don't wait for codes on the dash.
- The coolant must be G13 (purple) or compatible G12++, don't mix with the green G11 because EA189 engines don't tolerate it well.
- Multitronic oil and filter strictly every 50,000-70,000 km - the only way the CVT survives past 250,000 km without a mechatronic rebuild.
- When changing rear brake pads, always use diagnostics to retract the EPB actuators, never by hand, because the motor breaks.
Frequently asked questions
Is the Audi A6 C7 2.0 TDI reliable for daily driving in BiH?
Yes, but on the condition that you accept it isn't an Octavia. The engine is proven, but the surrounding systems and electronics are pricier. If the oil and services are kept up, and you don't buy the cheapest 300,000 km example with an unknown history, the A6 C7 will easily serve for years without major surprises.
How long does the timing chain last on the CGLC engine?
In practice between 180,000-250,000 km, depending on driving style and oil intervals. It isn't replaced preventively by age - we watch for the symptom (rattle on start-up) and code P0016. If you hear a rattle from the back of the engine when starting, come in immediately, don't wait for it to jump teeth.
Which A6 C7 engine is the best choice - CGLC or CSUA?
CGLC (2011-2014) is simpler, no AdBlue, fewer NOx sensors, cheaper diagnostics. CSUA (2014-2018) has fewer chain issues but needs AdBlue upkeep. For a used buy we recommend a CGLC with a solid service history - it's easier to maintain in BiH.
Is it worth installing autogas on the A6 C7 2.0 TDI?
No. The A6 C7 with the 2.0 TDI is a diesel and autogas isn't fitted to diesels as standard practice. If you drive a petrol model (A6 C7 2.0 TFSI or 3.0 TFSI), an autogas installation is possible and we do it - stop by for a consultation.
How much does a multitronic transmission service cost?
The price depends on the actual condition - get in touch for a quote. What matters is changing the oil and filter every 50,000-70,000 km, an investment that extends the gearbox's life by years.
Is it worth buying an A6 C7 with 250,000 km?
It can be worth it, but only with a pre-purchase inspection - especially the timing chain on CGLC, DPF, EGR cooler, multitronic and NOx sensors on CSUA. Bring the car to us for an inspection before buying; in an hour or two we'll tell you what to expect in the short and medium term.
Fault P0299 on an A6 C7 - what's going on?
P0299 means underboost - the turbo isn't delivering enough pressure. The most common causes: stuck VGT geometry, a leaking intercooler or hose, a faulty MAP sensor, or the turbo vacuum actuator. Don't replace the turbo blindly - first do diagnostics and check the vacuum system.
If you notice any of these symptoms on your A6 C7, drop by the workshop - it's better to check early than to repair expensively.