The performance petrol in the C7 A6 range, using a 3.0-litre supercharged V6 from the EA837 family. Smooth, powerful, and refined on the motorway, producing 300 hp (CGWB) or 310 hp (CGWD) before the facelift and 333 hp (CREC) after it. European models are paired exclusively with quattro and the 7-speed S-tronic DL501 dual-clutch gearbox. The supercharger gives instant throttle response without turbo lag, and the engine can reach well beyond 200,000 km with proper maintenance.· more· less
Strong and responsive supercharged V6Refined motorway cruiser
PCV and coolant repairs need supercharger removalS-tronic DL501 mechatronics risk
Buy if: You want a fast, refined executive saloon with a proven V6 and can find one with complete service history, preferably post-2013.
Avoid if: You need low running costs or cannot budget for the labor-intensive engine access required when repairs arise behind the supercharger.
Oil separator fails causing excessive oil consumption, rough idle, and vacuum leaks · more· less
The PCV valve (oil separator) is located underneath the supercharger, making replacement labor-intensive. The valve's diaphragm tears or its pressure regulation degrades, leading to excessive crankcase pressure. Symptoms include increased oil consumption (often the first sign), rough idle, misfires, and a check engine light. Pre-mid-2012 engines had a higher-pressure regulation valve that was more prone to failure; Audi released an updated part with lower pressure regulation. Failure typically occurs between 80,000 and 130,000 km. DIY cost is around €200-300 in parts, but professional replacement runs €1,200-1,800 at a dealer because the supercharger must be removed to access it. Independent specialists charge €400-900.
Water pump and thermostat failure
up to €1,4002 of 7
Plastic thermostat housing cracks and water pump leaks from bearing weep holes · more· less
Early 3.0 TFSI engines (2011-2012) had thermostats prone to sticking closed, causing overheating. Audi supplied updated parts. The water pump can leak from the bearing weep hole, typically between 70,000 and 120,000 km. Post-2013 engines received redesigned components with improved materials. Replacement cost at an independent shop runs €600-900 including parts and labor. Dealer quotes range from €1,000-1,400. Always check coolant level and condition during a pre-purchase inspection; low coolant or signs of overheating are red flags.
S-tronic DL501 mechatronics wear
up to €4,5003 of 7
Solenoid valves in the mechatronic unit wear out causing jerky shifts or limp mode · more· less
European A6 3.0 TFSI models use the 7-speed S-tronic DL501 wet dual-clutch gearbox. The mechatronic unit's solenoid valves are heavily stressed and can degrade over time, causing jerky gear changes, hesitation, EPC warning light, or gearbox fault messages. This typically appears between 100,000 and 180,000 km. The gearbox requires fluid changes every 60,000 km; neglecting this accelerates wear significantly. Dealer gearbox replacement quotes can reach €6,000-10,000, but specialist mechatronics repair or rebuild is possible for €1,500-2,500. Repair kits are available for €300-500 for competent DIY mechanics. Check for smooth shifts across all gears and listen for clunking during a test drive.
Timing cover oil leak
up to €4,0004 of 7
Upper and rear timing chain covers develop oil leaks, especially on higher-mileage engines · more· less
The timing chain covers at the rear of the 3.0 TFSI engine can develop oil leaks as the gaskets age. This is more common on engines with over 120,000 km. The rear timing cover is particularly expensive to repair because access requires significant disassembly, with some shops quoting 15-20 hours of labor. Upper timing cover leaks are somewhat easier to address. At an independent specialist, expect €1,500-2,500 for upper cover repair. Rear cover repair can reach €3,000-4,000 due to the extensive labor involved. If caught early, the leak is cosmetic and can be monitored, but it worsens over time.
Carbon buildup on intake valves
up to €1,2005 of 7
Direct-injection-only versions get no fuel washing the intake valves, leading to carbon deposits and rough running · more· less
On the direct-injection-only versions (CGWB and CGWD) no fuel washes the intake valves, so carbon deposits accumulate over time. The facelift CREC adds port injection alongside direct injection, which keeps the valves considerably cleaner. Symptoms include cold-start misfires, rough idle, reduced power, and poor fuel economy. The issue typically becomes noticeable between 80,000 and 130,000 km. The cleaning process (walnut blasting) requires removing the intake manifold and supercharger, which is a full day of labor. Cost at a specialist runs €600-900, while dealer pricing can reach €1,200. Using high-quality fuel and regular highway driving helps slow carbon buildup. Some owners perform this service preventively every 80,000-100,000 km.
Engine mount degradation
up to €1,0006 of 7
Hydraulic engine mounts sag or tear, causing vibrations and clunking at idle · more· less
The liquid-filled hydraulic engine mounts on the 3.0 TFSI are known to degrade over time, typically between 80,000 and 130,000 km. Symptoms include noticeable vibrations at idle, a rough feeling when stationary in gear, and clunking noises during acceleration or deceleration. Replacement involves both left and right mounts, as they tend to wear at similar rates. OEM mounts cost €120-200 each, with aftermarket options from €60-100. Labor runs €200-400 at an independent shop. Total replacement cost is €500-700 at an independent or €800-1,000 at a dealer. Upgraded aftermarket mounts from companies like 034 Motorsport may last longer than OEM.
Air suspension compressor failure (if equipped)
up to €2,5007 of 7
Optional air suspension compressor or struts can fail, typically after 80,000-120,000 km · more· less
Air suspension is an optional extra on the A6 C7. If equipped, the compressor and air struts are known weak points. The compressor can fail from overwork if air struts develop small leaks. Symptoms include the car sitting low on one corner, slow ride height adjustment, or a compressor that runs constantly. Replacement compressor costs €400-600 for parts, with labor adding €300-500. Individual air struts cost €500-800 each. Early C7 models (2011-2013) had a possibly problematic batch of compressors. Cars with standard steel springs avoid this issue entirely. During a test drive, check that all four corners sit level after the car has been parked overnight.
Reliable V6 with labor-intensive repair access
The 3.0 TFSI supercharged V6 is fundamentally a strong engine that can exceed 200,000 km with proper maintenance. However, the supercharger's position over the engine means that several common repairs (PCV valve, carbon cleaning, coolant work) require its removal, significantly increasing labor costs. Pre-2013 engines are more prone to thermostat and PCV issues. The S-tronic DL501 gearbox requires regular fluid changes to avoid expensive mechatronics problems. Later cars with documented service history represent the best value proposition, and the facelift arrived in October 2014.
Service history
Complete Audi dealer or specialist records essential. Verify oil changes at correct intervals and S-tronic fluid changes every 60,000 km.
Cold start
Must start engine completely cold. Listen for unusual rattles, knocking, or rough idle in the first 30 seconds.
Test drive
Minimum 30 minutes including highway speeds. Get the engine and gearbox fully up to temperature.
Tires and alignment
Check tread depth, age (date codes), and uneven wear. Inner edge wear can indicate control arm bushing problems.
Specific for this vehicle
Check oil level and consumption history
The 3.0 TFSI can consume oil when the PCV valve is degraded. Ask the seller about top-up frequency. More than 0.5 litres per 1,000 km indicates a problem.
Check coolant level and condition
Low coolant or milky/brown appearance is a red flag. Look for coolant stains around the supercharger area and thermostat housing.
Test all S-tronic gearbox functions
Drive for 20+ minutes. Check for smooth upshifts and downshifts, no hesitation from standstill, no jerking in low-speed traffic. Test reverse gear specifically.
+ 4 more checksShow less
Look for oil leaks on timing covers
Inspect the rear of the engine (from below) for oil seepage around the timing chain covers. Some moisture is normal; active dripping is concerning.
Check engine mounts
With the car in Drive and foot on the brake, check for excessive vibration at idle. Rev and release; listen for clunking.
Air suspension level check (if equipped)
After the car has been parked overnight, check all four corners are level. Uneven height indicates a leaking strut or failing compressor.
MMI and electronics function test
Test all infotainment functions, Bluetooth, navigation, parking sensors, and camera. Check for software update status.
Recalls and Technical Service Bulletins
Takata airbag inflator, French official scope covers A6 production to 2011 only (verify by VIN and market)Verify completed
Fuel rail leak on early 3.0 TFSI cars (2011 - 2012 production, German A6)Critical - verify completed
Fuel system leak risk, campaign 24DP for type 4G cars produced September 2013 - April 2018Critical - verify completed
Contact an Audi dealer with the VIN to verify all recall actions have been completed. Both fuel-leak campaigns are the priority items on this engine, and between them they cover most of the production run. Campaign codes circulated for the 3.0 TFSI often come from Audi of America and do not transfer to European cars, so check each one against the VIN and the market of first registration.
Warranty Status
Factory warranty (2 years, no km limit)Expired on all used A6 C7 models
Rust perforation warranty (12 years)May still apply on 2014+ models
All A6 C7 models are outside their original 2-year factory warranty. Ask an Audi dealer whether any goodwill contribution is available on a documented PCV valve failure, as the repair can exceed €1,500. Extended warranty plans may be available through Audi or third-party providers.
Sources: Research draws on model-specific owner forums and owner communities, recall information from official authorities, German automotive press, and multiple workshop cost references cross-checked against each other.
This report is for informational purposes only and does not constitute professional advice. Estimates may be inaccurate. Always have a qualified specialist inspect the vehicle before purchase. We accept no liability for decisions made based on this information.
