Audi A7 4G

Proven V6 diesel with 150 kW. Smooth-running six-cylinder with good pulling power. Timing chain instead of cam belt, therefore less maintenance-intensive in the valvetrain.

• !! Timing Chain Rattle on Cold Start from 150,000 km

  Chain tensioners lose oil pressure on cold start; chain slaps until pressure builds. If elongated, chain skip with engine damage is possible. Older production years with four chains are significantly more susceptible.

  Symptoms: Metallic rattling or clattering from the engine bay directly after cold start, disappears within a few seconds
  2,500–3,500 $
  Ad timing chain 3.0 TDIchain tensioner CDUCEA897 timing chain
• !! Camshaft Material Defect (272 hp Variants) from 80,000 km

  Material defect in camshafts of the CRT variant (272 hp) causes tooth flank wear before 100,000 km. Knocking engine noises, in worst case engine damage.

  Symptoms: Ticking or knocking engine noises clearly beyond normal diesel clatter
  3,500–5,000 $
  Ad camshaft 3.0 TDI CRTEA897 camshaft
• !! Turbocharger Oil Loss / Leaking Oil Lines from 130,000 km

  Oil lines below the turbocharger develop leaks. Oil consumption rises gradually, blue smoke from the exhaust. Complex repair as the gearbox and turbocharger must be removed.

  Symptoms: Blue smoke from exhaust, dropping oil level, power loss, whistling under load
  1,200–2,500 $
  Ad turbocharger 3.0 TDI CDUCÖlleitung turbocharger EA897

+ 2 more engine weaknesses + vehicle weaknesses

V6 diesel with 180 kW. Best-selling engine in the A6 C7. Effortless performance for heavy saloons and estates; excellent long-distance engine.

• !! Camshaft fracture — material defect from 100,000 km

  In the 3.0 TDI CLAA (204 hp) the camshaft can break due to a material defect, causing immediate engine damage. Audi documented the issue in TPI 2043172. Affected production years 2015–2017. Camshafts were sometimes replaced free of charge under goodwill.

  Symptoms: Knocking or ticking engine noises beyond normal diesel clatter, sudden engine failure, timing chain fault codes
  3,500–20,000 $
  Ad camshaft 3.0 TDI CLAA059109021camshaft 3.0 TDI V6
• !! Timing chain elongation from 150,000 km

  The 3.0 TDI V6 has four timing chains: two per cylinder bank for the camshafts, one connecting chain, and one for the oil pump. Elongation leads to incorrect valve timing and can cause catastrophic engine damage. Replacement requires 15–20 labour hours.

  Symptoms: Rattling on cold start, camshaft fault codes in ECU, rough running, power loss
  2,000–4,000 $
  Ad timing chain 3.0 TDI V6chain tensioner 3.0 TDI059109229timing chain CLAA
• !! High-pressure pump debris in fuel system from 160,000 km

  When the high-pressure pump fails, metal debris can contaminate the entire diesel system and damage the injectors. Audi A5/A6 with 3.0 TDI are affected. A full system flush and replacement of pump and injectors is then required, incurring very high costs.

  Symptoms: Starting problems, irregular engine running, fuel pressure fault, metallic noise from the engine bay
  1,500–12,000 $
  Ad high-pressure fuel pump 3.0 TDI057130755injection pump CLAA V6Common Rail pump 3.0 TDI

+ 3 more engine weaknesses + vehicle weaknesses

3.0-litre TDI V6 with 245 PS (C7 generation, EA897). Four-chain timing system — complex and maintenance-intensive; check for chain replacement from 150,000 km if rattling. Camshaft material defect known in early EA897 batches; check service history for camshaft replacement. Cam belt to CR pump every 120,000 km.

• !! Camshaft fracture from material defect from 80,000 km

  The 3.0 TDI EA897 in newer models is affected by camshaft fractures due to material defects. Audi acknowledged the issue via TPI 2043172. Primarily vehicles from production years 2014–2017.

  Symptoms: Ticking engine noises exceeding normal diesel combustion levels, increasing power loss, then engine failure
  3,500–20,000 $
  Ad camshaft 3.0 TDI CKNBcamshaft EA897camshaft A6 Q7 TDI 272
• !! Timing chain elongation from 120,000 km

  Chain elongation and tensioner wear on the 3.0 TDI CKNB can lead to the chain jumping a tooth. A full overhaul takes 15–20 hours, costing roughly €3,000 upwards.

  Symptoms: Rattling on cold start and under load, timing fault codes in OBD, occasional misfires
  2,500–4,500 $
  Ad timing chain CKNBtiming chain 3.0 TDI EA897chain tensioner A7 Q7 TDI
• !! Turbocharger wear and bearing damage from 150,000 km

  The bi-turbo 3.0 TDI shows turbocharger wear, partly from inadequate oil supply or deposits. Damage often occurs at high mileage or after long oil-change intervals.

  Symptoms: Whistling noise from the engine bay, blue exhaust smoke, power loss especially under load, elevated oil consumption
  1,500–4,000 $
  Ad turbocharger 3.0 TDI CKNBturbocharger V6 TDI A6 A7 Q7Lader 272 PS TDI

+ 2 more engine weaknesses + vehicle weaknesses

Revised V6 diesel with 160 kW after facelift. Optimised emissions treatment with dual SCR dosing. Smooth-running and economical.

• !! Camshaft wear — material defect from 100,000 km

  The 3.0 TDI CZVA (218 hp) is affected by the known camshaft material defect. Audi TPI 2043172 covers CZV engine variants as well. Affected serial numbers are from early production (a few thousand engines). Camshaft fracture inevitably leads to total engine damage.

  Symptoms: Ticking or knocking noises beyond normal TDI clatter, camshaft control faults, power loss
  3,500–20,000 $
  Ad camshaft 3.0 TDI CZVA059109021camshaft V6 TDI 218PS
• !! Four-chain timing system elongation from 140,000 km

  The V6 3.0 TDI CZVA uses a four-chain timing system plus a toothed belt for the high-pressure fuel pump. The belt must be changed every 120,000 km. Chain elongation occurs primarily when oil maintenance is neglected and requires a complex repair.

  Symptoms: Rattling on cold start, camshaft phase faults, fuel system messages, power loss
  2,000–4,500 $
  Ad timing chain 3.0 TDItiming belt fuel pump 3.0 TDI059109229chain tensioner CZVA
• !! EGR valve coking — V6 TDI from 100,000 km

  The EGR system on the 3.0 TDI V6 CZVA is prone to coking from the high soot content in the exhaust gas. Sticking EGR valves reduce engine power and increase fuel consumption. Complete jamming can cause mechanical valve failure and additional costs.

  Symptoms: Power loss, increased fuel consumption, poor take-off, rough idle, fault code P0401
  400–1,200 $
  Ad EGR valve 3.0 TDI V6059131501EGR valve CZVA

+ 2 more engine weaknesses + vehicle weaknesses

V6 diesel with 200 kW in the BiTDI variant after facelift. Highest output of the 3.0 TDI. Powerful drivetrain with electrically driven compressor.

• !! Camshaft Material Defect (CRT/CZV) from 100,000 km

  Material defect on camshafts of EA897 engines (272 hp and 218 hp) built 2014 to early 2017. A broken camshaft causes total engine failure. Audi performed goodwill repairs where service history was complete.

  Symptoms: Loud ticking or knocking from the engine bay clearly exceeding diesel combustion noise; often occurs on cold start or under load
  3,500–20,000 $
  Ad camshaft 3.0 TDI EA897059109101camshaft set CRT
• !! Timing Chain Stretch — Four Chains from 150,000 km

  The 3.0 TDI V6 uses four timing chains. From around 160,000 km cold-start rattling occurs. Timing chain replacement requires extensive engine removal and costs €1,500–4,500.

  Symptoms: Cold-start rattle that disappears as the engine warms up; engine check light; rough running
  2,500–5,000 $
  Ad timing chain 3.0 TDI V6059109229chain tensioner EA897
• !! Engine Damage from Low Oil Pressure (EA897evo) from 180,000 km

  The variable oil pump in the EA897evo reduces oil pressure at low rpm for Euro 6 optimisation. With fuel-diluted oil viscosity drops, which can lead to seizure damage.

  Symptoms: Rising oil level (fuel in oil), oil pump clatter, abrupt engine damage possible without warning
  8,000–25,000 $
  Ad oil pump 3.0 TDI EA897injector CRT CRTE059130277

+ 2 more engine weaknesses + vehicle weaknesses

V6 biturbo diesel with 230 kW. Twin-turbocharged six-cylinder for maximum pulling power. Complex design leads to higher maintenance costs.

• !! Exhaust Manifold Particles Damage High-Pressure Turbo from 100,000 km

  The inner lining of the air-gap-insulated exhaust manifold detaches over time. Metal particles enter the turbine wheel of the small high-pressure turbocharger and destroy it. Both parts must be replaced.

  Symptoms: Loud whistling or metallic rattling from the turbo, significant power loss especially below 2,000 rpm, delayed boost pressure buildup
  2,500–6,000 $
  Ad exhaust manifold 3.0 BiTDI CGQBturbocharger Hochdruck 3.0 TDI059145715059145721
• !! Camshaft Material Defect (EA897) from 100,000 km

  Like all EA897 third-generation engines, CGQB units are susceptible to camshaft breaks from material defects. Mainly affects vehicles from production period 2014–2017.

  Symptoms: Loud, unusual knocking or ticking from the engine bay; sound differs from normal diesel combustion noise
  3,500–15,000 $
  Ad camshaft 3.0 BiTDI059109101 CGQBcamshaft kit EA897
• !! Timing Chain 1.2 TFSI EA111 — Early Failure from 50,000 km

  The EA111 1.2 TFSI (CGQB) suffers from severe timing chain problems from as early as 30,000–40,000 km. Defective tensioners and worn guide rails lead to chain jump and total engine loss.

  Symptoms: Clattering rattle on cold start, engine warning light, in worst case sudden engine shutdown.
  700–3,000 $
  Ad timing chain CGQB 1.2 TFSIchain tensioner EA111 1.2 TSI Audi A1timing chain kit 1.2 TFSI

+ 3 more engine weaknesses + vehicle weaknesses

Supercharged V6 with 228 kW. Powerful and rev-happy engine, but the supercharger drive belt is a known wear item.

• !! Internal Supercharger Intercooler Leaking from 150,000 km

  The integrated intercooler in the Eaton supercharger fails due to thermal fatigue. Coolant enters the cylinders via the intake — risk of hydraulic lock engine damage.

  Symptoms: Coolant loss without external leaks, cylinder 3 misfires, white exhaust cloud, power loss.
  1,000–2,500 $
  Ad intercooler intern CGWB A6 C7 3.0 TFSIIntercooler supercharger gasket EA837Eaton Intercooler 3.0 TFSI A7
• !! Chain Tensioner Rattle on Cold Start from 60,000 km

  As across the EA837 family, the upper chain tensioners in the CGWB lose oil pressure at rest. Brief cold-start rattle. CGWB-specific: missing check valves in the oil passage accelerate pressure loss.

  Symptoms: Metallic rattle 1–2 seconds after engine start, fades as oil pressure rises. Persistent noise with damaged chain guides.
  1,200–2,000 $
  Ad chain tensioner CGWB 3.0 TFSI A6 C7timing chain obere chain CGWBchainnführung EA837 A6
• !! Coolant Pump and Thermostat Failure from 100,000 km

  Coolant pump and thermostat fail at high mileages. A6 C7 with 3.0 TFSI also has engine mount problems around 50,000 km that increase thermal stress.

  Symptoms: Temperature gauge fluctuates or rises too high, coolant loss, cold engine on start despite warm-up.
  400–1,200 $
  Ad water pump CGWB 3.0 TFSI A6 C7thermostat EA837 A6 A7 3.0 TFSIcoolantkreislauf CGWB

+ 5 more engine weaknesses + vehicle weaknesses

Supercharged V6 with 245 kW after facelift. Most powerful supercharger variant of the EA837 in A6/A7. Excellent long-distance engine.

• !! Internal Intercooler Leaking from 130,000 km

  Coolant leakage into the integrated supercharger intercooler is particularly critical in the CTUA due to the higher boost pressure (245 kW) — hydraulic lock is possible.

  Symptoms: Coolant loss, white exhaust cloud, cylinder 3 misfires, power loss.
  1,000–2,500 $
  Ad intercooler intern CTUA S6 A6 C7 3.0 TFSIIntercooler Eaton supercharger 245 kW EA837gasket intercooler CTUA
• !! Chain Tensioner Rattle on Cold Start from 60,000 km

  EA837-typical: upper chain tensioners lose oil pressure at rest, brief rattle on cold start. The CTUA as the performance variant (S6) runs under higher thermal load.

  Symptoms: Brief metallic rattle after cold start, gone after 1–2 seconds. With wear, permanent chain noise.
  1,200–2,000 $
  Ad chain tensioner CTUA 3.0 TFSI S6 A6 C7timing chain EA837 245 kWchainnführung CTUA A7 Sportback
• !! Coolant Pump Failure from 100,000 km

  Coolant pump and thermostat fail at high mileages. S6/A7 3.0 TFSI at 245 kW places high demands on the cooling system.

  Symptoms: Overheating warning, coolant loss, unstable temperature gauge.
  400–1,200 $
  Ad water pump CTUA 3.0 TFSI S6coolant pump EA837 CTUA A7 A6thermostat 3.0 TFSI 245 kW

+ 4 more engine weaknesses + vehicle weaknesses

Hot-V design: both turbos sit in the V-angle between the cylinder banks, directly above the exhaust system. This shortens charge pipes and delivers lightning-fast response without noticeable turbo lag, but concentrates heat and oil stress in one place. Audi had to issue recall 21H7 in 2022 for all vehicles built between 2012–2017: an overly fine oil strainer in the turbo oil circuit clogged — total turbo failure in many cases. The sound is muted by engine encapsulation, but has character. The overall performance — 560 PS, eight-speed Tiptronic, quattro — makes the C7 RS6/RS7 the most competent everyday fast car of its era. Always verify recall status before purchase.

• !! Recall 21H7 — oil strainer blocks turbo supply

  The overly fine oil strainer in the oil feed to both turbochargers can become blocked with carbon deposits, cutting off turbo lubrication. KBA recall 21H7 for vehicles up to March 2017 (12,204 in Germany).

  Symptoms: Sudden power loss, misfires, in the worst case complete engine failure without warning
  0–500 $
  Ad Ölsieb 4.0 TFSI079103175G check valverecall 21H7
• !! Camshaft wear — head and shaft as a unit from 150,000 km

  The camshafts are factory-matched to their respective cylinder heads; on wear, the head and camshaft must be replaced as a unit, which significantly increases repair costs.

  Symptoms: Ticking from the valvetrain, rough running, power loss at high rpm
  5,000–15,000 $
  Ad camshaft 4.0 TFSI CWUBcamshaft RS6 C7 V8
• !! Timing chain stretched — V8 chain drive from 160,000 km

  Complex chain drive; idle fluctuations with camshaft synchronisation fault codes may indicate stretched chains or broken guide rails.

  Symptoms: Rattling on cold start, idle fluctuations, camshaft position fault codes (P0017, P0022)
  3,000–8,000 $
  Ad timing chain 4.0 TFSItiming chain Kit V8 EA824chain tensioner CWUB

+ 7 more engine weaknesses + vehicle weaknesses

Performance variant of the 4.0 TFSI with 605 PS — same Hot-V architecture as CWUB, sharper mapping, larger turbos, freer exhaust flow. Recall 21H7 (oil strainer in the turbo oil circuit) affects the CRDB just as it does the CWUB — essential to verify it has been completed before purchase. Noticeably more direct throttle response and more aggressive character in Dynamic mode compared to the base CWUB. Sport differential and lowered suspension standard. The C7 Performance is considered the sweet spot of the range: no OPF, no mild hybrid, sharpest tune — owners who then drive the C8 reportedly miss the sharper throttle response and the unfiltered V8 sound.

• !! Turbocharger Bearing Failure from Oil Starvation from 60,000 km

  Both turbochargers can fail simultaneously if the oil strainer clogs and interrupts bearing lubrication. Primarily affects 2012–2017 model years before the recall; even brief oil starvation causes total failure.

  Symptoms: Loud whistling or screeching from the engine bay, power loss, engine stalling under high load
  4,000–12,000 $
  Ad turbocharger RS6 C7turbo CRDB 4.0 TFSI06E145601 turbocharger
• !! Recall: Turbocharger Oil Strainer Too Fine from 60,000 km

  The oil strainer in the turbocharger oil circuit is too fine-mesh and clogs with soot and oil deposits. This leads to insufficient turbo bearing lubrication and can cause engine failure. Recall 21H7.

  Symptoms: Sudden power loss, engine failure while driving, no prior warning from indicator lights
  0–0 $
  Ad turbocharger S6 C7 4.0 TFSIoil strainer turbo CRDBturbo bearing RS6 C706E145601
• !! Camshaft Wear-In from 100,000 km

  The camshafts on the 4.0 TFSI wear in because they are factory-matched to specific cylinder heads and deteriorate with insufficient oil supply. Replacement often requires cylinder head overhaul.

  Symptoms: Ticking or knocking from the valve train, engine roughness, uneven idle, camshaft fault codes
  2,000–6,000 $
  Ad camshaft S6 C7 4.0 TFSIcamshaft CRDBcamshaft adjuster 4.0 TFSI

+ 7 more engine weaknesses + vehicle weaknesses

Biturbo V8 with 309 kW for S6/S7 C7 and S8 D4. Detuned version of the RS V8 with cylinder deactivation. Comfortable and powerful at the same time.

• !! Recall 21H7 — Oil Strainer Turbocharger Supply from 60,000 km

  KBA recall (code 21H7) for S6 and RS6 built June 2012 to March 2017: the too-fine oil strainer restricts turbocharger lubrication. Replacement with a coarser-mesh strainer required. Without repair, turbo damage can result.

  Symptoms: Power loss, whistling turbo noise, engine check light; in advanced cases metallic swarf in oil
  0–500 $
  Ad oil strainer turbocharger 4.0 TFSIoil filter strainer S6 S7079115561
• !! Timing Chain Stretch — V8 BiTurbo from 170,000 km

  At high mileages (150,000–200,000 km) 4.0 TFSI engines show timing chain stretch, recognisable by camshaft synchronisation faults. Repair requires extensive engine work on the V8.

  Symptoms: Idle fluctuations, camshaft synchronisation fault codes, rattling on cold start from the front timing drive
  3,000–8,000 $
  Ad timing chain 4.0 TFSI V8079109158chain kit CTGA V8
• !! High-Pressure Fuel Pump — Wear from 140,000 km

  The high-pressure fuel pump on the 4.0 TFSI is a known wear component. Pressure loss causes injection problems and uneven combustion. Wear increases with long service intervals or poor fuel quality.

  Symptoms: Rough running, injection noise, power loss at high rpm, cold-start problems
  800–2,500 $
  Ad high pressure pump 4.0 TFSI079127026fuel pump V8 CTGA

+ 7 more engine weaknesses + vehicle weaknesses