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Audi · Known Issues

1995-2025 Audi A6 Problems: 23 Known Issues

1995-2025 model years · NHTSA recalls, manufacturer TSBs, and owner forum reports · Updated September 2026

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Issue summary

According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 1995-2025 Audi A6 has 23 documented known issues, with 9 rated critical. The most serious are 48V Belt Starter-Generator Warning and VIN-Specific Campaigns, Timing belt/tensioner failure causes catastrophic valve-piston contact ($900-$4,500 repair), C5 A6 2.7T Low Boost or Smoke - Diagnose the System Before Buying a Turbo, Headlight-Switch Wiring Fire Recalls JC and JN ($0-$0 repair), Tie-Rod Seal Failure Recalls 99V-248 and 00V-414 ($0-$0 repair), 2006 A6 Multitronic 01J Delayed D/R Engagement - Check the Axial-Seal TSB, C5 A6 Bosch 5.3 ABS Warning or No Communication - Identify and Test Before Module Work, Gateway Control Module Liquid-Ingress Recall 90V2 (22V-861) ($0-$0 repair) and Timing Chain Tensioner Failure (3.2L V6 & 4.2L V8) ($3,000-$12,000 repair). Across all issues with published estimates, repair costs range from $100 to $12,000. DIY maintenance guides at au7o.io.

In This Article

  • A6 Electrical7
  • A6 Engine7
  • A6 Brakes2
  • A6 Steering1
  • A6 Transmission1
  • A6 Suspension2
  • A6 Body/Panels1
  • A6 Cooling1
  • A6 Emissions1
  • Recalls14
  • FAQ
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In This Article

  • Electrical7
  • Engine7
  • Brakes2
Steering
1
  • Transmission1
  • Suspension2
  • Body/Panels1
  • Cooling1
  • Emissions1
  • Recalls14
  • FAQ
  • All 23 Known Issues

    Filter:
    ALL YEARS2025202420232022202120202019201820172016201520142013201220112010200920082007200620052004200320022001200019991998199719961995

    When Issues Typically Appear

    2.7T Ignition Coil Pack Failure Causing Misfires and Flashing Check Engine Light
    40K-120K
    Timing belt/tensioner failure causes catastrophic valve-piston contact
    60K-105K
    Front Suspension Multi-Link Control Arm and Tie-Rod Wear Causing Clunks and Tire Wear
    60K-130K
    Timing Chain Tensioner Failure (3.2L V6 & 4.2L V8)
    80K-120K
    Water Pump and Thermostat Failure (Overheating)
    80K-120K
    038K75K113K150K mi

    A 48V electrical-system warning on a mild-hybrid A6 is not repaired with an ordinary 12V battery, charger, alternator, or starter. Certain 2019-2020 2.0T mild-hybrid vehicles are covered by safety recall 27H2 or 20V-153 for moisture intrusion into the belt starter generator, which can cause a short circuit, smoldering, or fire. Audi also issued VIN-specific service action 27BQ for qualifying later vehicles. Outside those campaigns, the exact Audi fault code and symptom number matter: U046900 with symptom 34763 and actual mode 8 can point to another CAN or sensor fault, and Audi states that replacing the starter generator will not fix that case.

    Common Symptoms

    • 48V electrical-system warning
    • Electrical-system malfunction message
    • Burning odor, smoke, or smoldering from the engine compartment on recall-affected vehicles

    How to Fix

    Check the VIN with Audi for open 27H2, 20V-153, or 27BQ work before authorizing parts. Follow Audi's safety instructions for an open fire-risk campaign and have the dealer perform the remedy. For a warning outside an open campaign, use Audi ODIS-guided diagnosis and preserve the complete code, symptom number, and actual mode. U046900 or P0CA700 alone is not permission to order a starter generator. Audi must select the correct starter-alternator suffix and associated hardware by VIN and guided-test result. Do not buy any of the former Optima, ACDelco, Battery Tender, Denso, or Remy 12V products for this 48V fault.

    Find a Audi dealer

    Choose to share your location for this search, or enter an area below. Your search location is sent to Google to find dealers.

    Open Audi dealer map in Google Maps ↗

    Call to confirm they service Audi vehicles and check your VIN, recall eligibility, parts availability, and appointment options.

    What you need to fix it

    Only diagnosis- and fitment-reviewed repair parts are linked here.

    Check your VIN for an open recall before buying.A dealer repairs an open manufacturer recall at no charge. Confirm coverage with NHTSA first.
    • 48V belt starter generator and campaign hardware (VIN-specific dealer selection)

      Quantity 1 only when an open campaign or Audi guided diagnosis requires replacement. The part suffix and hardware are VIN-specific; no consumer commerce link is safe.

    Owner tips & cautions

    • TipSave a scan showing the full Audi symptom number and actual mode. U046900 by itself is not enough to select a starter generator.
    • WarningA conventional 12V battery, trickle charger, starter, or alternator cannot substitute for the 48V campaign remedy or guided diagnosis.

    Research This Issue

    GoogleRedditYouTubeNHTSA
    NHTSA Verified
    High ConfidenceVerifiedReviewed Jul 2026

    Audi recall 04V-133 (campaign JC) covers certain 1998-2004 A6 and S6 vehicles because the headlight-switch wiring harness can contact the driver's-side crossmember area, eventually shorting and creating a fire risk in the left dashboard. Audi later issued recall 06V-198 (campaign JN) for certain 1998-2004 A6 Sedan and Avant vehicles equipped with halogen low beams because pins in the headlight-switch connector could contact each other, overheat, or cause a fire. The JN campaign excludes xenon-equipped vehicles, including S6 models, but those vehicles may still fall within the earlier JC campaign. Eligibility must be checked by VIN.

    Common Symptoms

    • Burning-plastic odor from the left side of the dashboard
    • Smoke or unusual heat near the driver's knee bolster
    • Headlight-switch or exterior-lighting malfunction

    How to Fix

    Check the VIN with Audi and have every open JC or JN campaign completed by an authorized dealer at no charge. The JC procedure installs protective material at the crossmember and inspects the wiring harness; the JN procedure reroutes the circuit with a jumper wiring harness. Do not buy a switch or generic harness as a substitute for the campaign remedy. If there is a burning-plastic odor, smoke, heat, or headlight-switch malfunction, stop safely, switch the vehicle off, exit, and contact emergency services if fire or smoke is present.

    Find a Audi dealer

    Choose to share your location for this search, or enter an area below. Your search location is sent to Google to find dealers.

    Open Audi dealer map in Google Maps ↗

    Call to confirm they service Audi vehicles and check your VIN, recall eligibility, parts availability, and appointment options.

    What you need to fix it

    Only diagnosis- and fitment-reviewed repair parts are linked here.

    Check your VIN for an open recall before buying.A dealer repairs an open manufacturer recall at no charge. Confirm coverage with NHTSA first.
    • Headlight-switch wiring recall remedy (JC or JN campaign-dependent)
      $0

      Audi verifies the applicable campaign by VIN and performs the protective-cover or jumper-harness repair free of charge.

    Owner tips & cautions

    • TipAsk Audi to check both campaign codes JC and JN by VIN; completing one campaign does not prove that the other is closed.
    • WarningTreat a burning odor, smoke, or unusual heat at the left dashboard as a fire warning. Stop safely and leave the vehicle rather than continuing to drive.
    Typical repair cost:$0 - $0

    Research This Issue

    GoogleRedditYouTubeNHTSA
    NHTSA Verified
    High ConfidenceVerifiedReviewed Jul 2026

    Certain 2019-2022 Audi A6 Sedan and 2020-2022 A6 allroad vehicles are included in safety recall 22V-861, Audi campaign 90V2. Liquid spilled on the rear seat can reach the gateway control module beneath the rear middle seat. If the module detects implausible signals or internal short circuits, its safety strategy can shut down gateway communication. Multiple warnings can appear and engine power can be reduced unexpectedly. Audi states that the engine remains running in emergency mode and that steering and braking remain available; the earlier claim that this recall causes complete engine shutdown was inaccurate.

    This issue also affects: Audi Q5 Sportback, Audi S7

    Common Symptoms

    • Multiple warning messages appear after liquid is spilled on the rear seat
    • Engine power is reduced and the vehicle enters emergency mode
    • Gateway communication faults affect several vehicle systems

    How to Fix

    Check the VIN in Audi's official recall lookup and have an authorized Audi dealer complete campaign 90V2 if it is open. The recall remedy is installation of a protective cover over the gateway control module at no charge. Do not buy a scanner, repair manual, or replacement gateway module as the recall fix. If warning messages or sudden reduced power occur, move out of traffic safely and arrange prompt dealer diagnosis; a module already affected by liquid requires vehicle-specific diagnosis and campaign or warranty handling.

    Find a Audi dealer

    Choose to share your location for this search, or enter an area below. Your search location is sent to Google to find dealers.

    Open Audi dealer map in Google Maps ↗

    Call to confirm they service Audi vehicles and check your VIN, recall eligibility, parts availability, and appointment options.

    What you need to fix it

    Only diagnosis- and fitment-reviewed repair parts are linked here.

    Check your VIN for an open recall before buying.A dealer repairs an open manufacturer recall at no charge. Confirm coverage with NHTSA first.
    • Gateway control module protective-cover recall remedy
      $0

      An authorized Audi dealer verifies campaign 90V2 by VIN and installs the protective cover free of charge.

    Owner tips & cautions

    • TipEnter the VIN in Audi's campaign lookup; model and year alone cannot confirm whether 90V2 is open on a particular A6.
    • WarningMultiple warnings and sudden reduced engine power require prompt dealer diagnosis. A generic OBD scanner or replacement module is not the recall remedy.
    Typical repair cost:$0 - $0

    Research This Issue

    GoogleRedditYouTubeNHTSA
    NHTSA Verified
    High ConfidenceVerifiedReviewed Jul 2026

    Audi TSB 2053875/1 applies to 2019 A6 vehicles equipped with MIB2+. The documented condition is a flickering lower MMI/HVAC display or streaked colored horizontal lines. Audi attributes it to a hardware problem in the upper MMI screen that corrupts image data sent to the lower display. In some vehicles the main unit stores U10E300, 'Multimedia display unit 2: no communication.' This is not evidence that every black screen, reboot, climate-control complaint, or 2019-2025 A6 MMI fault has one cause, and the previous broad MIB3 claim combined distinct generations and failure modes.

    Common Symptoms

    • Lower MMI/HVAC display flickers
    • Lower display shows streaked colored horizontal lines
    • U10E300 may be stored in main unit address 005F

    How to Fix

    Confirm that the vehicle is a 2019 A6 with MIB2+ and that the symptom matches the lower-screen distortion/flicker described in Audi TSB 2053875/1. Scan address 005F for U10E300 and complete Audi's guided diagnosis. For the documented condition, the TSB directs the technician to replace the top display and operating unit in the instrument panel. Audi instructs the parts department to use current ETKA information, including supersessions, so there is no safe universal part number or retail link for this record; select the unit by VIN. Other black-screen, reboot, camera, connectivity, or control faults require their own diagnosis rather than automatic display replacement.

    What you need to fix it

    Only diagnosis- and fitment-reviewed repair parts are linked here.

    • Top MMI display and operating unit

      Quantity 1 only after the 2019 MIB2+ condition in TSB 2053875/1 is confirmed. Audi requires the current ETKA part and supersession to be selected by VIN.

    Owner tips & cautions

    • TipRecord a short video of the flicker or colored lines and note whether U10E300 is stored; this helps distinguish the documented display fault from unrelated MMI complaints.
    • WarningDo not buy a generic relay, scanner, multimeter, or used display as the fix. Audi calls for guided diagnosis and current ETKA/VIN selection of the display unit.

    Research This Issue

    GoogleRedditYouTubeNHTSA
    NHTSA Verified
    High ConfidenceVerifiedReviewed Jul 2026

    Audi TSB 2064983/1 covers 2021-2022 A6 models equipped with Audi Virtual Cockpit Gen2+. A red, green, or blue continuous vertical line can appear through the instrument-cluster display; Audi identifies this as a hardware issue in the Virtual Cockpit. This is distinct from the older C5 segmented center-display problem. The previous record duplicated that C5 issue, mixed pixel loss with gauge dropouts and cluster resets, and attached generic searches for pixel repair and a battery maintainer even though neither item is the Audi-specified remedy for this hardware condition.

    Common Symptoms

    • Continuous red vertical line through the Virtual Cockpit display
    • Continuous green vertical line through the Virtual Cockpit display
    • Continuous blue vertical line through the Virtual Cockpit display

    How to Fix

    Confirm that the vehicle is a 2021-2022 A6 with Virtual Cockpit Gen2+ and that the complaint is a continuous red, green, or blue vertical line. Photograph the line in focus with a date and VIN reference, as Audi directs. The bulletin specifies replacement of instrument cluster J285 at address 0017 according to ELSA, with the exact cluster selected through ETKA for the VIN. Cluster programming, coding, immobilizer/security, mileage, and driver-information functions make a generic used or retail cluster unsafe. Check warranty/CPO eligibility, then use an Audi dealer or properly equipped specialist for the documented replacement and adaptation. No universal product link is published.

    Owner tips & cautions

    • TipTake a sharp photo showing the full colored line and retain a VIN/date reference before the appointment; Audi's bulletin requests that documentation.
    • WarningDo not order a generic LCD, ribbon, or used cluster. The bulletin specifies a VIN-selected J285 replacement through ETKA/ELSA with the required programming and adaptation.

    Research This Issue

    GoogleRedditYouTubeNHTSA
    Manually Verified
    High ConfidenceVerifiedReviewed Jul 2026

    The Audi A6 is prone to various electrical gremlins across all generations, including window regulator failures, door lock actuator failures, MMI/infotainment glitches, and battery drain issues. Window regulators fail due to weak plastic clips in the mechanism, causing windows to drop into the door or move slowly. Door lock actuators wear out, causing doors to unlock randomly, fail to lock, or make grinding noises. MMI (Multi Media Interface) infotainment systems freeze, reboot randomly, or display "SAFE" mode. Battery drain issues (parasitic draw) are common, leaving the car dead after sitting for a few days. Many electrical issues are caused by aging control modules, corroded connectors, or software bugs. While frustrating, most electrical issues are not safety-critical and can be addressed individually as they arise.

    Common Symptoms

    • Window drops into door or won't roll up/down
    • Door locks fail to lock or unlock (one or more doors)
    • Grinding or clicking noise from door when locking
    • MMI screen freezes, reboots, or shows "SAFE" mode
    • Battery dies after car sits for 2-3 days
    • Warning lights for systems that work fine (phantom codes)
    • Backup camera, parking sensors, or adaptive cruise intermittent

    How to Fix

    Window regulator replacement: $300-$600 per window (DIY $150-$250 with aftermarket kit). Order regulator with metal clips, not plastic. Door lock actuator: $200-$400 per door at dealer, DIY $50-$100 per actuator (1-hour job). MMI/infotainment glitches: Perform hard reset (hold power + volume up for 10 seconds). If that fails, Audi dealer can update software or replace MMI unit ($1,000-$2,500). Battery drain: Have dealer perform parasitic draw test to identify faulty module. Common culprits: trunk electronics, MMI, comfort control module. Address issues as they arise—most are minor annoyances, not showstoppers.

    What you need to fix it

    Only diagnosis- and fitment-reviewed repair parts are linked here.

    • Genuine Audi front-left window regulator, motor not included
      OEM4F0837461DCross-ref4F0837461C (previous revision)

      Quantity 1 only for a mechanically confirmed front-left regulator failure on the C6 A6. Confirm VIN and door position before ordering.

      eBayFCP Euro

    As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

    Owner tips & cautions

    • TipListen for the motor and watch whether the glass tilts before buying anything. Motor noise with poor glass movement points toward the mechanical regulator; silence requires an electrical diagnosis first.
    • Warning4F0837461D is front-left and does not include the motor. It is not the right part for another door position or for a failed switch, motor, door module, or lost one-touch setting.
    • WarningThe front door contains a side-airbag sensor. Follow the factory battery and airbag safety procedure before disassembling the window frame.
    Typical repair cost:$100 - $2,500

    Research This Issue

    GoogleRedditYouTubeNHTSA
    Community Reported
    Medium Confidence

    A C5 A6 center driver-information display can develop missing rows, segments, fading, or an unreadable image while the analog gauges and the rest of the cluster continue to operate. That display-only complaint must be separated from a whole cluster that resets, loses power, drops gauges, or has communication/charging faults. The previous card asserted one ribbon-adhesive root cause for every vehicle, assigned unsupported mileage and cost ranges, and described 1998-1999 used-cluster swaps as easy without primary evidence. Audi's later C5 service information shows that complete cluster replacement can require VIN, immobilizer, key, odometer/service, and coding work, so a random used cluster is not a safe universal fix.

    Common Symptoms

    • Missing horizontal rows or segments in the center display
    • Center display fades or becomes difficult to read when warm
    • Driver-information or warning text is unreadable while analog gauges remain normal

    How to Fix

    Photograph the display cold and warm, confirm whether only the center LCD is affected, and scan address 17 while checking battery/charging voltage and cluster power/ground if the entire unit resets or gauges drop. Record the cluster's full Audi/VDO label and software identity. For an LCD-only fault, a qualified instrument-electronics specialist can evaluate repair of the original cluster, which may preserve its coding and vehicle data; do not buy a loose ribbon or LCD solely from a model-year search because cluster/display variants differ. If the complete cluster must be replaced, follow Audi's VIN-specific replacement, coding, saved-value, immobilizer, and key-adaptation procedure. Because the exact display variant is not known from the card, no retail part link is published.

    Owner tips & cautions

    • TipRepairing the original cluster can avoid a replacement-unit identity mismatch, but use a specialist who verifies the exact cluster/display variant and preserves vehicle data.
    • WarningGauge dropouts, resets, or a fully dead cluster are not the same as center-LCD pixel loss. Diagnose supply, charging, communication, and cluster faults before ordering display parts.
    • WarningDo not assume a used cluster is plug-and-play. Audi's C5 procedure can require VIN transfer, coding, immobilizer/key adaptation, and saved service/odometer values.

    Research This Issue

    GoogleRedditYouTubeNHTSA
    Manually Verified
    Medium ConfidenceVerifiedReviewed Jul 2026

    The 2.8L V6 (both 12V AAH in the C4 1995-1997 and 30V AHA/ATQ in the C5 starting 1998) is an interference engine, so timing belt, tensioner, idler, or hydraulic damper failure between service intervals will allow the valves to strike the pistons, bending valves and sometimes cracking pistons. The hydraulic tensioner damper on the 30V is a well-known weak point — owners report aftermarket 'OEM-quality' dampers collapsing within about a week of installation, causing audible belt slap. Audi's most recent recommended belt-replacement interval is 75,000 miles (some older service booklets referenced 105,000 miles, and earlier model-year intervals were shorter).

    Common Symptoms

    • belt slap or slapping noise at idle
    • ticking from front of engine
    • sudden engine stall and no-restart
    • bent valves / no compression after failure
    • check engine light

    How to Fix

    Replace the timing belt as a complete kit (belt, tensioner roller, tensioner lever, hydraulic damper, idler/relay roller, and water pump) at or before the service interval — do not just replace the belt. Use OEM or reputable brands (NTN for the hydraulic damper, INA for idler bearings, Continental/ContiTech for the belt); forum reports document cheap aftermarket dampers failing within days. The hydraulic damper must be compressed slowly to avoid irreversible internal damage. Camshaft alignment bar (Audi tool 3242) and crankshaft lock pin (Audi tool 3391) are required to set timing accurately on the 30V. Parts kit runs roughly $300-600; a full job at an independent shop typically runs $900-1,800. Catastrophic failure repair (valves, possible head work) commonly runs $2,500-4,500+.

    What you need to fix it

    Only diagnosis- and fitment-reviewed repair parts are linked here.

    • Gates timing-belt kit with water pump for 1999 A6/A6 Quattro 2.8L
      Cross-refGates TCKWP297, Dayco WP297K1A, Continental PP297LK1

      Quantity 1 for the catalog-confirmed 1999 A6 or A6 Quattro 2.8L AHA application. Confirm VIN/engine code and kit contents before opening or installing; do not use this link for the earlier 12-valve engine or a different model year withou…

      eBay

    As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

    Owner tips & cautions

    • WarningDo not order from the old 078109119J search alone. This service depends on the exact engine application and a complete, known kit; verify the VIN, AHA engine code, and included components first.
    • TipPhotograph the engine code and existing timing marks, record the installed kit and date, and keep the invoice so the next owner can verify service history.
    • WarningA maintenance kit cannot repair bent valves. If the engine lost timing, confirm mechanical damage before ordering normal service parts.
    Typical repair cost:$900 - $4,500

    Research This Issue

    GoogleRedditYouTubeNHTSA
    Community Reported
    High ConfidenceLast reported by owners May 2026Reviewed May 2026

    The 2000-2002 C5 A6 Quattro 2.7T APB uses two position-specific turbochargers plus wastegate control, N75 regulation, recirculation valves, vacuum plumbing, charge-air hoses/intercoolers, crankcase ventilation, and separate oil/coolant connections. Low boost, noise, or exhaust smoke does not identify a turbocharger or a side by itself. Audi's diagnostic information specifically requires a leak-tight vacuum/charge system and notes that a recirculation valve or vacuum-line fault can produce no boost and rumbling. The previous card treated those symptoms as a predictable heat/oil failure across 2000-2004, added unsupported mileage and cost ranges, and sent every owner to a right-side 078145702R search before the failed component or bank was known.

    This issue also affects: Audi A1, Audi A3, Audi S7

    Common Symptoms

    • Measured boost is below specification after test conditions are met
    • Blue or gray exhaust smoke whose source has not yet been isolated
    • Whine, rumble, or mechanical noise under boost
    • Oil present in charge plumbing beyond the level a technician considers normal
    • Loss of power or boost-control fault that may also be caused by leaks or control components

    How to Fix

    Save DTCs and freeze-frame, then compare commanded and measured boost using the factory test conditions. Pressure- or smoke-test the intake and charge-air path; inspect intercoolers, clamps, vacuum hoses, both recirculation valves, N75 control, wastegate operation, crankcase ventilation, and oil/coolant leakage. Determine whether smoke is entering through the intake, exhaust, or crankcase system. A turbo specialist should confirm wheel damage, housing contact, bearing/shaft condition, or a failed seal and identify bank/side before parts are ordered. If a turbocharger is mechanically confirmed failed, match the APB engine, VIN, transmission, left/right position, and current Audi/BorgWarner revision; follow the factory procedure for new seals/fasteners, oil and coolant connections, cleanliness, and pre-lubrication. Because neither the current symptom record nor ShowMeTheParts establishes a failed side, this card intentionally provides no turbo purchase link.

    Owner tips & cautions

    • WarningDo not order 078145702R from the old card merely because the car has low boost or smoke. It is a position-specific turbo reference, while the 2.7T uses a left/right pair and several cheaper faults can mimic turbo failure.
    • TipAsk the diagnosing shop to document commanded versus measured boost, the leak-test result, the confirmed failed bank/side, engine code, and turbo identification plate before quoting parts.
    • WarningShowMeTheParts supplies a mounting-gasket-set candidate for this YMME but no turbocharger candidate. That gasket result does not establish which turbo, if any, needs replacement.

    Research This Issue

    GoogleRedditYouTubeNHTSA
    Manually Verified
    High ConfidenceVerifiedReviewed Jul 2026

    The C6 A6 with the 3.2L V6 and 4.2L V8 engines suffers from timing chain tensioner failures due to wear over time. Audi designates the chains and tensioners as "lifetime" parts requiring no maintenance, but they fail as early as 80,000-120,000 miles. The 3.2L engine has 4 chains, 3 tensioners, and several guides—all prone to wear. A loud rattling or clicking noise on cold start from the upper rear of the engine is the classic symptom of failing tensioners. If ignored, the timing chain can jump or break, causing catastrophic valve-to-piston contact and complete engine destruction. The transmission must be removed for full access, making this a labor-intensive repair. AudiWorld forums report low-mileage cars with stretched chains due to the design flaw.

    This issue also affects: Audi A4, Audi A1, Audi A5

    Common Symptoms

    • Rattling or clicking noise from rear of engine on cold start
    • Metallic clattering that disappears after engine warms up
    • Check engine light with timing/cam correlation codes (P0016, P0017)
    • Rough idle or hesitation
    • Engine won't start (if chain has jumped)
    • Severe engine damage if chain breaks (bent valves, destroyed pistons)

    How to Fix

    PREVENTIVE REPLACEMENT: Replace ALL timing chains, tensioners, and guides at 80,000-100,000 miles before failure occurs. The repair requires removing the transmission for access. Labor is 15-20 hours. Replace oil pump chain as well. Use OEM Audi parts only—aftermarket tensioners fail quickly. If rattling has started, DO NOT delay—engine damage can occur within weeks. Some owners opt for engine replacement ($8,000-$12,000) if severe damage has occurred. Class action settlement may cover some costs for 2004-2008 models.

    What you need to fix it

    Only diagnosis- and fitment-reviewed repair parts are linked here.

    • Bank 2 (left) upper timing-chain tensioner
      OEM06E109217AMCross-ref06E109217AH

      Confirm VIN and engine before ordering; do not use this link for a 2011 A6 without Audi VIN confirmation.

      ECS Tuning
    • Bank 1 (right) upper timing-chain tensioner
      OEM06E109218APCross-ref06E109218AJ

      Confirm VIN and engine before ordering; do not use this link for a 2011 A6 without Audi VIN confirmation.

      ECS Tuning

    As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

    Owner tips & cautions

    • TipRecord a true first-start-of-the-day video. The Audi TSB is limited to a brief one-to-three-second cold-start rattle.
    • WarningDo not use this TSB to self-diagnose persistent rattle, warm-engine noise, rough running, a no-start, or cam-crank correlation faults.
    Typical repair cost:$3,000 - $12,000

    Research This Issue

    GoogleRedditYouTubeNHTSA
    Community Reported
    Medium Confidence

    Water pump failures are common across all A6 generations due to plastic impeller degradation and seal leaks. Audi uses plastic impellers that crack or disintegrate over time (typically 80,000-120,000 miles), causing coolant leaks and overheating. The water pump is often driven by the timing belt or timing chain, so replacement is recommended during timing service to save labor. Thermostat housings also crack due to heat cycling, causing coolant leaks and erratic temperature readings. Symptoms include coolant leaks under the car, overheating in traffic, temperature gauge fluctuations, and coolant warning lights. Ignoring a failed water pump can lead to severe engine overheating, warped cylinder heads, and blown head gaskets ($3,000-$5,000 repair). Some models have electric auxiliary water pumps that also fail, causing poor heater performance.

    This issue also affects: Audi Q7, Audi A4, Audi A5 Sportback

    Common Symptoms

    • Coolant leak under front of car (pink/green puddle)
    • Overheating in stop-and-go traffic or at idle
    • Temperature gauge rising above normal (middle position)
    • Coolant warning light or low coolant message
    • No heat from cabin heater (auxiliary pump failure)
    • Hissing or gurgling noise from engine bay
    • Steam or coolant smell from engine

    How to Fix

    Replace water pump AND thermostat together ($800-$1,500 with labor). Always use OEM or high-quality aftermarket parts (Rein, Hepu)—cheap pumps fail within 20,000 miles. If water pump is timing belt/chain driven, replace during timing service to save labor. Flush cooling system and refill with OEM Audi G12++ or G13 coolant (do NOT mix types). Inspect coolant hoses and replace if cracked. If auxiliary electric water pump fails, replace separately ($300-$600). Monitor coolant level weekly and address leaks immediately to prevent overheating damage.

    What you need to fix it

    Only diagnosis- and fitment-reviewed repair parts are linked here.

    • Beck/Arnley 131-2517 main engine water pump
      Cross-refBeck/Arnley 131-2517

      Confirm VIN and current fitment before ordering; this is not an auxiliary water pump.

      eBay

    As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

    Owner tips & cautions

    • TipPhotograph the suspected leak before cleaning it, then recheck after the system is filled and the car is driven. The Audi bulletin requires the leak to be reproduced rather than inferred from old residue.
    • WarningConfirm that the failed component is the main engine coolant pump. The A6 also has auxiliary pumps, and those are different parts with different repair roles.
    Typical repair cost:$800 - $1,500

    Research This Issue

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    Community Reported
    Medium Confidence

    For a 2019-2021 Audi A6 equipped with the 3.0L TFSI engine, the malfunction indicator lamp may illuminate with P0300 and one or more cylinder-specific P0301-P0306 codes. Audi's service information identifies an applicable ECM software-calibration condition and publishes model-year-specific software levels. Misfire codes alone do not prove intake-valve carbon buildup, and the previous card incorrectly grouped 2011-2023 A6 models, multiple unrelated engine generations, a fixed walnut-blasting interval, fuel additives, universal catch cans, and generic shopping searches into one diagnosis. This corrected record covers only the Audi-documented software condition; carbon cleaning or parts replacement requires separate physical diagnosis if the misfire remains after the software level and other common causes are checked.

    This issue also affects: Audi S8, Audi A4, Audi A1

    Common Symptoms

    • Malfunction indicator lamp or check-engine light illuminated
    • P0300 random/multiple-cylinder misfire stored
    • One or more P0301-P0306 cylinder-specific misfire codes stored

    How to Fix

    Record every stored DTC and freeze-frame before clearing faults. Confirm that the vehicle is a 2019-2021 A6 with the 3.0L engine, then have an Audi dealer or qualified VAG specialist compare the ECM J623 part number and software version with Audi's bulletin and perform the specified Software Version Management update when applicable. For MY2019 the bulletin lists 4K0907559A version 0007 updating to 0008 with SVM action 01A255; MY2020 lists 4K0907559D version 0002 updating to 0003; MY2021 lists 4K0907559K versions 0001-0002 updating to 0004. Recheck for misfires after the update. If faults persist, diagnose ignition, plugs, injectors, fuel quality, air leaks, compression, and only then inspect the intake valves before authorizing cleaning. Do not buy a catch can, cleaner, ignition part, or walnut-blasting service solely from P0300-P0306.

    Owner tips & cautions

    • TipSave the complete scan and freeze-frame before an update or repair. The cylinder pattern and operating conditions are useful if the misfire remains.
    • WarningP0300-P0306 do not identify carbon buildup by themselves. Verify the Audi software level and diagnose the remaining possible causes before paying for walnut blasting or ordering parts.
    • WarningThe published fix is software, so ShowMeTheParts cannot validate it and no retail product link belongs on this record.

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    Manually Verified
    High ConfidenceVerifiedReviewed Jul 2026

    The 2.7T V6 used in A6 2.7T models is well known for ignition coil pack failures that cause sudden misfires, rough running, and loss of power. This issue was widespread across many early-2000s Audi/VW turbo models and generated numerous owner complaints and service actions. Failures may occur one cylinder at a time or in repeated succession as the coils age.

    This issue also affects: Audi S8, Audi TT, Audi A4

    Common Symptoms

    • rough idle
    • flashing check engine light
    • loss of power under acceleration
    • engine shaking
    • misfire under boost
    • poor fuel economy

    How to Fix

    Scan for cylinder-specific misfire faults, inspect spark plugs, and swap suspect coils to confirm the fault follows the coil. The standard repair is replacement of the failed coil packs; many owners replace the full set and install updated revision coils. Spark plugs should be checked or replaced at the same time if worn or fuel-fouled.

    What you need to fix it

    Only diagnosis- and fitment-reviewed repair parts are linked here.

    • APB engine ignition coil (confirmed failed cylinder only)
      OEM058905105

      Quantity 1 per confirmed failed cylinder; six are installed. Confirm the engine code before ordering.

      ECS Tuning
    • BEL engine ignition coil (confirmed failed cylinder only)
      OEM06A905115D

      Quantity 1 per confirmed failed cylinder; six are installed.

    As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

    Owner tips & cautions

    • TipLabel the coils before swapping them and rescan after the swap. A misfire that stays on the original cylinder points away from the coil.
    • WarningDo not use recall 04V-133 as coil evidence; it is the A6 headlight-switch wiring and fire-risk recall.
    Typical repair cost:$120 - $500

    Research This Issue

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    Community Reported
    High Confidence

    Audi training material for the later CREC 3.0T explains that a magnetic-supercharger-clutch click, brief hoot, or perceived hesitation during engagement can be normal. Primary evidence does not support the former broad claim that every 2012-2018 A6 develops a replaceable nose-cone bearing failure. The former 06E145475 part was not validated across that year range, the claimed 034-145-Z001 product could not be verified, and G052300A2 is A/C refrigerant-compressor oil rather than a scheduled supercharger-oil service product.

    Common Symptoms

    • Click or brief hoot when the magnetic supercharger clutch engages
    • Perceived hesitation that coincides with clutch engagement

    How to Fix

    Do not order a nose-cone bearing from noise alone. Confirm the CREC engine and localize the sound, compare operation with a similar-mileage vehicle, and follow Audi's magnetic-clutch and belt diagnostic process. Check for boost or drivability faults and distinguish normal clutch engagement from an accessory-drive, clutch, pulley, bearing, or complete-supercharger fault. Select a part only after the exact failed component and VIN fitment are established. No owner-buyable part is published for this record until that diagnosis exists.

    Owner tips & cautions

    • TipRecord when the sound occurs and whether it coincides with magnetic-clutch engagement; that timing is essential to diagnosis.
    • WarningDo not add G052300A2 to the supercharger. It is A/C compressor refrigerant oil, not a scheduled supercharger-oil service product.

    Research This Issue

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    Manually Verified
    High ConfidenceVerifiedReviewed Jul 2026

    Some 1998-2001 C5 A6 configurations use Bosch 5.3 brake electronics, but Audi documents several ABS/EDL, ASR, and ESP versions with engine- and transmission-specific coding. An ABS lamp, red brake warning, wheel-speed fault, or failure to communicate with address 03 does not by itself prove an internal control-module fault. Power, ground, connector, CAN communication, wheel-speed inputs, hydraulic/electrical tests, module identity, and coding must be checked. The previous card asserted a specific internal bond-wire defect and very high failure frequency across every 1998-2004 A6, then linked 8E0998375 without proving that kit or system version matched the vehicle.

    Common Symptoms

    • ABS warning lamp remains on after the startup check
    • Red brake warning or traction/ESP warning accompanies the ABS lamp
    • Address 03 does not communicate after vehicle power, ground, and network checks
    • Wheel-speed or coding faults are stored and require system-specific diagnosis

    How to Fix

    Treat an active red brake warning as a safety issue and follow the owner's-manual stopping guidance. Use a VAG-capable scan tool to identify address 03, record the exact Audi/Bosch part and software number, coding, and all DTCs. Verify battery voltage, fuses, module power and grounds, connector condition, CAN communication, and all four wheel-speed signals using Audi's electrical test tables before condemning J104. Identify whether the vehicle has ABS/EDL, ABS/EDL/ASR, or ESP and record engine, transmission, VIN, and option/PR information. If the control module or hydraulic-control assembly is proven faulty, use the factory catalog and coding procedure for that exact configuration. A third-party repair of the original electronics may preserve identity, but it is not an Audi factory internal repair and should be selected only after the original module number and failure are confirmed. This card intentionally has no universal replacement or rebuild link.

    Owner tips & cautions

    • WarningDo not order 8E0998375 or a used ABS unit from the old card. Match the label, Bosch system version, VIN/PR equipment, engine, transmission, and coding first.
    • TipSave an address-03 scan and a photo of the Audi/Bosch label before removing anything. A no-communication result is meaningful only after power, ground, connector, and network checks pass.
    • WarningBase braking feel does not prove ABS/EDL/ASR/ESP is working. Follow warning-lamp safety guidance until the brake-electronics fault is resolved.

    Research This Issue

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    Manually Verified
    High ConfidenceVerifiedReviewed Jul 2026

    Audi TSB 2037761/1 covers a specific situation in which a 2012-2015 A6 shows ABS/ESP warnings and the engine does not switch off with a normal press of START ENGINE STOP. The ignition system uses the ABS control unit's vehicle-speed signal to determine whether the car is stationary. A control-module/signal fault can remove that signal; prolonged wheel slip in winter can also make wheel speeds appear implausible and temporarily deactivate ABS even when there is no permanent system error. The previous record duplicated the older C5 Bosch-module card and sent users to a 4B0614517P search without establishing vehicle generation, DTC, system version, or a failed module.

    Common Symptoms

    • ABS or ESP warning is shown in the instrument cluster
    • A normal press of START ENGINE STOP does not switch off the engine while stopped
    • The condition may follow loss of the ABS speed signal or prolonged winter wheel slip

    How to Fix

    Bring the vehicle to a complete stop in a safe location. Audi states that below 6 mph (10 km/h), the emergency-off function is activated by holding START ENGINE STOP while pressing the brake pedal. Diagnose the vehicle according to the stored DTCs rather than ordering an ABS module from the warning alone. If the warning followed sustained winter wheel slip, Audi notes that the system may become fully active again after the ignition is switched off and the vehicle is restarted; persistent warnings still require diagnosis. Do not use the emergency-off procedure while driving except as described by the owner's manual and Audi safety information. This informational bulletin specifies no replacement part, so this record has no commerce link.

    Owner tips & cautions

    • WarningStop safely before using the emergency-off function. At speeds below 6 mph, Audi specifies holding START ENGINE STOP while pressing the brake pedal.
    • TipSave the full DTC scan and the conditions that preceded the warning, including sustained wheel slip. The bulletin directs diagnosis by DTC and does not identify a universal ABS replacement part.

    Research This Issue

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    Manually Verified
    High ConfidenceVerifiedReviewed Jul 2026

    Certain 1998-1999 Audi A6 vehicles were included in safety recalls 99V-248 and 00V-414 for tie rods whose seals might not keep moisture and dust out of the swivel-bearing mechanism. Contamination can accelerate wear and create excessive play, reducing steering control. Clunking, wandering, uneven tire wear, a damaged boot, or visible play are reasons for an immediate steering inspection, but they do not identify one universal outer tie-rod part number for every affected A6.

    Common Symptoms

    • Steering looseness or measurable play
    • Front-end clunking
    • Vehicle wanders or will not track straight
    • Uneven front-tire wear
    • Damaged tie-rod seal or boot

    How to Fix

    Check the VIN with NHTSA and Audi for open recall 99V-248 or 00V-414 work and have an authorized dealer perform any open remedy at no charge. The recall history involves tie-rod replacement, not one generic retail outer end. If no campaign is open but looseness or boot damage is present, have a qualified shop inspect the complete inner and outer tie-rod assemblies on both sides, select the correct updated parts by VIN and steering configuration, replace only after diagnosis, and perform a wheel alignment. Do not drive a vehicle with measurable steering play until it is judged safe.

    Find a Audi dealer

    Choose to share your location for this search, or enter an area below. Your search location is sent to Google to find dealers.

    Open Audi dealer map in Google Maps ↗

    Call to confirm they service Audi vehicles and check your VIN, recall eligibility, parts availability, and appointment options.

    What you need to fix it

    Only diagnosis- and fitment-reviewed repair parts are linked here.

    Check your VIN for an open recall before buying.A dealer repairs an open manufacturer recall at no charge. Confirm coverage with NHTSA first.
    • Tie-rod recall remedy (VIN and inspection determine the required assemblies)
      $0

      Quantity and position are inspection-dependent. Audi checks campaign eligibility and steering configuration before selecting inner or outer tie-rod assemblies.

    Owner tips & cautions

    • TipUse both the Audi and NHTSA VIN lookups because campaign eligibility is VIN-specific, not guaranteed by model year alone.
    • WarningDo not order the former 8E0419811B search result as the universal fix. Inner versus outer position, side, and steering configuration must be established first.
    Typical repair cost:$0 - $0

    Research This Issue

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    NHTSA Verified
    High ConfidenceVerifiedReviewed Jul 2026

    Audi TSB 2013280/4 addresses a specific loss-of-pressure condition in Multitronic transmissions produced from May 2005 through May 2006. The vehicle may not move or may engage Drive or Reverse only after a delay and increased engine speed; P1743/18151 may be stored. Audi attributes the covered condition to production-damaged axial seals, but its repair depends on the selected direction and measured transmission values. The previous card incorrectly treated every 2005-2011 C6 A6 transmission complaint as inevitable chain/hydraulic failure, claimed complete replacement was usually the only economical repair, mixed transmission families, and linked a generic rebuilt-mechatronic search. This corrected record applies only when the vehicle actually has the front-wheel-drive 01J Multitronic and falls in the bulletin's production window.

    Common Symptoms

    • No movement or delayed movement after Drive is selected
    • No movement or delayed movement after Reverse is selected
    • Engine speed must be raised before the vehicle begins to move
    • P1743/18151 clutch-slip-monitoring fault may be stored

    How to Fix

    First identify the transmission code and vehicle production date; Quattro/09L and other transmissions are outside this repair. Scan the TCM and retain the printout. For P1743/18151, Audi directs the technician to inspect MVB 44/1 and 45/1: 1000 mA with pressure above 12 bar points to the axial seals, while pressure below 12 bar indicates a different hydraulic problem. If no fault is logged, Audi specifies an adaptation drive with ATF temperature above 90 C, then assessment of MVB 10/1. For a Drive complaint with MVB 10/1 above 380 mA, the bulletin calls for four valve-body axial seals 01J301547F. For a Reverse complaint, it calls for those four valve-body seals plus input-shaft seal 01J301547A and the corresponding transmission work. If the production range, direction, DTC, temperature, or measurements do not match, continue Guided Fault Finding instead of buying seals or a transmission. These are internal, condition-dependent parts; verify current Audi supersessions and quantities through the VIN before repair.

    Owner tips & cautions

    • WarningDo not assume an A6 has Multitronic from the model year alone. Confirm front-wheel drive, transmission code 01J, and the May 2005-May 2006 production window before using this bulletin.
    • TipAsk for the TCM scan, ATF temperature, complaint direction, and MVB 10/1, 44/1, and 45/1 values in writing. Those values determine whether the seal repair applies.
    • WarningThe old rebuilt-mechatronic search was removed. Audi's bulletin does not authorize a mechatronic unit or complete transmission merely from delayed engagement, and ShowMeTheParts has no axial-seal candidate for this YMME.

    Research This Issue

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    Manually Verified
    High ConfidenceVerifiedReviewed Jul 2026

    The C5 A6 uses a multi-link aluminum front suspension with multiple upper and lower control arms whose ball joints and bushings commonly wear out, especially on rough roads or higher-mileage cars. Owners frequently report front-end clunking over bumps, wandering steering, vibration, and uneven inner-edge tire wear. This is one of the most commonly discussed C5 chassis wear items across owner forums and repair databases.

    This issue also affects: Audi TT, Audi A4

    Common Symptoms

    • clunking over bumps
    • front-end looseness
    • wandering steering
    • uneven front tire wear
    • steering vibration
    • knocking noise from front suspension

    How to Fix

    Diagnosis usually involves checking for play in the upper and lower control arm ball joints, torn bushings, and worn tie-rod ends with the suspension loaded. The durable repair is replacement of the failed arms, and many owners replace the full front control-arm kit at once followed by a four-wheel alignment. Tie rods and sway-bar links are often inspected or replaced at the same time.

    What you need to fix it

    Only diagnosis- and fitment-reviewed repair parts are linked here.

    • Delphi TC1400KIT complete front suspension control-arm kit
      Cross-refDelphi TC1400KIT

      Manufacturer and ShowMeTheParts fitment is 1998-2001 A6/A6 Quattro, all engines; not verified for 2002-2004 or allroad. Confirm VIN before ordering.

      eBay

    As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

    Owner tips & cautions

    • TipAsk the inspector to identify the exact arm, side, and failed joint in writing. This prevents a generic front-end noise from turning into an unnecessary complete-kit order.
    • WarningDo not final-tighten bonded-rubber-bushing fasteners with the suspension hanging. Use the factory curb-weight or control position to avoid preloading and shortening bushing life.
    • WarningTC1400KIT is confirmed here only for 1998-2001 A6/A6 Quattro. A 2002-2004 A6 or an allroad needs a separate VIN-specific parts lookup.
    Typical repair cost:$600 - $1,800

    Research This Issue

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    Community Reported
    High Confidence

    Audi TSB 2062932/1 describes an informational diagnostic issue on 2018-2021 A6/A7 vehicles with adaptive suspension. During PDI or diagnosis, ODIS address 0074 may show accumulator or system pressure above 25 bar even though that is not the actual pressure; some J775 suspension-control-module versions report the measuring value incorrectly. The previous card instead claimed that 2012-2018 Premium Plus and Prestige A6 sedans commonly burn out compressors at a fixed mileage, assigned 1,400 owner reports without source evidence, and recommended Arnott P-3250, relay 8K0951253, and compressor 4G0616005C without proving the vehicle had adaptive air suspension or that any of those parts matched.

    Common Symptoms

    • ODIS address 0074 displays accumulator or system pressure above 25 bar
    • The finding may occur during PDI or diagnosis with no customer complaint
    • Displayed pressure does not agree with a physical system-pressure measurement

    How to Fix

    First confirm by VIN/PR equipment that the vehicle has adaptive suspension. If ODIS address 0074 shows accumulator or system pressure above 25 bar, do not condemn the compressor from that value. Audi specifies using air-suspension leak-detection tester VAS 751 001 to measure actual pressure and evaluate compressor output. A real sag, leak, run-time, or ride-height complaint still requires the separate factory leak, valve-block, air-spring, relay, wiring, temperature-protection, and compressor diagnostics for that VIN. Replace a compressor only after measured output and the rest of the air-supply system identify it as failed. This bulletin itself specifies a diagnostic tool rather than a replacement part, so the old product links are removed.

    Owner tips & cautions

    • WarningDo not replace the compressor, relay, or air springs solely because ODIS displays more than 25 bar. Audi says that displayed value may be incorrect.
    • TipAsk the shop to document the VIN/PR equipment and the physical VAS 751 001 pressure result, not only the address-0074 screen value.

    Research This Issue

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    Manually Verified
    High ConfidenceVerifiedReviewed Jul 2026

    The federal Dewey settlement record identifies 1998-2005 Audi A6 C5 vehicles with the 4B platform code, including allroad, S, and RS versions, among vehicles alleged to be susceptible to passenger-compartment water ingress through sunroof drains or the fresh-air plenum. This page-level record is conservatively scoped to 1998-2004 A6 model years so it is not shown as a universal condition on a 2005 C6 sedan; a 2005 allroad owner should confirm the 4B platform by VIN. Audi A6 C5 repair literature shows separate front and rear sunroof drain hoses and a cable-based cleaning procedure. Wet footwells or headliner do not prove that a drain hose itself needs replacement: debris, a restricted outlet, a disconnected or damaged hose, and the fresh-air plenum are different paths that must be checked separately. Water left under the carpet can damage electrical modules and wiring.

    Common Symptoms

    • Water in a front or rear footwell after rain or a car wash
    • Damp or stained headliner or pillar trim
    • Musty odor or persistent interior-window fogging
    • Electrical faults after water accumulates beneath the carpet

    How to Fix

    Confirm the 4B platform/VIN and trace the leak before buying parts. Test each sunroof drain separately with a modest amount of water, then clean a blocked hose with the proper sunroof-drain snake or the flexible cable method described in the repair manual. Inspect each hose connection and outlet as well as the fresh-air plenum; replace a hose only when it is found disconnected, kinked, split, or otherwise damaged. The hose part number depends on body style, position, and VIN, so it must be selected from Audi's catalog after diagnosis. Remove and dry wet carpet and padding promptly and inspect any affected electrical modules or connectors. The previously listed 4A9877233 hose was not verified for this C5 application and is not a safe universal repair.

    Owner tips & cautions

    • TipWater-test one drain at a time and confirm where it exits. A wet footwell can come from the plenum rather than the sunroof tray.
    • WarningDry both the carpet and the thick padding beneath it promptly; the surface can feel dry while water remains around wiring and modules.
    • WarningDo not order a universal drain hose from this symptom alone. Confirm the failed position, body style, and VIN in the Audi parts catalog first.

    Research This Issue

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    Manually Verified
    High ConfidenceVerifiedReviewed Jul 2026

    Audi repair literature for the C5 2.8L AHA engine identifies a rear coolant pipe and multiple sealed cooling-system connections. Owner reports on 2.8L AHA/ATQ cars also show why a leak at the rear of the engine cannot be assigned to one O-ring from symptoms alone: coolant can escape from a rear pipe connection, a heater-hose connector, the coolant-temperature-sensor connection, or another nearby joint and then run toward the transmission. The previous card mixed the different 2.7T layout into the 2.8L record, extended the claim through 2005, and prescribed four identical N90560701 seals without sufficient fitment evidence. This corrected record is limited to the 1998-2001 C5 A6 2.8L AHA/ATQ application and treats the visible leak location as a diagnosis, not a universal part order.

    Common Symptoms

    • Slow or recurring coolant loss
    • Sweet coolant odor after driving
    • Fresh coolant or dried residue at the rear of the engine
    • Coolant tracking toward the transmission or bellhousing area
    • Low-coolant warning if the leak progresses

    How to Fix

    With the engine cold, clean and dry the rear cooling-system connections and pressure-test the system using the Audi repair procedure. Trace fresh coolant to the exact joint before disassembly; specifically distinguish the rear coolant-pipe connections from the heater hoses/connectors and coolant-temperature-sensor seal. Replace only the pipe, hose, connector, or seal that is proven to leak, and renew any seals or gaskets the repair manual marks for replacement. Select every seal by VIN, engine code, and exact diagram position in the current Audi catalog. Refill with the correct Audi-compatible coolant and bleed and re-pressure-test the system. Do not order N90560701 from this card: the audit did not establish it as the correct universal seal or quantity for the 2.8L AHA/ATQ layout. Stop driving if the coolant warning or temperature rises, because continued coolant loss can cause overheating.

    Owner tips & cautions

    • TipClean the area before pressure testing and photograph the first fresh trace of coolant. Coolant running down the engine can make the lowest wet point look like the source.
    • WarningA rear-engine leak on the 2.8L can come from a heater-hose connector rather than the crossover-pipe seals. Confirm the exact joint before removing the intake or ordering parts.
    • WarningDo not treat a 2.7T seal listing or a generic O-ring kit as proof of 2.8L fitment. Match the VIN, engine code, seal dimensions, and diagram position.

    Research This Issue

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    Manually Verified
    Medium ConfidenceVerifiedReviewed Jul 2026

    Audi emissions service action 17F9 covers certain 2011-2014 vehicles equipped with the 2.0L TFSI engine, including affected A6 vehicles in the 2012-2014 model-year range. The pressure-regulating valve diaphragm may be damaged and the vehicle may fail an emissions inspection. Eligibility is VIN-specific. The former record incorrectly combined this 2.0T campaign with the different 3.0T crankcase-ventilation assembly and promoted an unrelated diaphragm kit, valve cover, and catch can as interchangeable fixes.

    This issue also affects: Audi A4, Audi A3, Audi A5

    Common Symptoms

    • Vehicle may fail an emissions inspection
    • Pressure-regulating valve diaphragm is damaged during campaign inspection

    How to Fix

    Check the VIN with Audi and ask whether service action 17F9 is applicable or already complete. The Audi procedure inspects the pressure-regulating valve and, when the inspection calls for it, installs repair kit 06H198542A. Do not order the former 06H103495AK search result, Dorman diaphragm, 3.0T valve-cover assembly, or catch can as the campaign remedy. A 3.0T A6 or a vehicle with ongoing drivability or oil-consumption symptoms requires a separate engine-specific diagnosis.

    Find a Audi dealer

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    Call to confirm they service Audi vehicles and check your VIN, recall eligibility, parts availability, and appointment options.

    What you need to fix it

    Only diagnosis- and fitment-reviewed repair parts are linked here.

    Check your VIN for an open recall before buying.A dealer repairs an open manufacturer recall at no charge. Confirm coverage with NHTSA first.
    • Pressure-regulating valve repair kit
      OEM06H198542A$0

      Quantity 1 only when the 17F9 inspection procedure calls for replacement. Dealer and VIN check first; no retail purchase is needed for an open service action.

    Owner tips & cautions

    • TipHave Audi check service action 17F9 by VIN before buying a crankcase-ventilation part.
    • WarningThis record is for the 2.0L TFSI campaign only. The 3.0T uses different components and must not be matched to this repair kit by model name alone.
    Typical repair cost:$0 - $0

    Research This Issue

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    Recall Related
    High ConfidenceVerifiedReviewed Jul 2026
    NHTSA Recalls14 recalls

    SEAT BELTS:REAR/OTHER:RETRACTOR

    Volkswagen Group of America, Inc. (Audi) is recalling certain 2025 SQ6 E-Tron, SQ6 Sportback E-Tron, Q6 Sportback E-Tron, A6, A5, A6 Sportback E-Tron, Q6 E-Tron, S5, and S6 Sportback E-Tron vehicles. The automatic locking retractor may fail to engage when a child seat is installed using the seat belt. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) numbers 208, "Occupant Crash Protection" and 209, "Seat Belt Assemblies."

    Campaign #25V89900019/12/2025

    BACK OVER PREVENTION: SENSING SYSTEM: CAMERA

    Volkswagen Group of America, Inc. (Audi) is recalling certain 2019-2026 vehicles. Please see the recall report for a complete list of models. A software error may prevent the rearview camera image from displaying as intended. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 111, "Rear Visibility."

    Campaign #25V90000019/12/2025

    ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM)

    Volkswagen Group of America, Inc. (Audi) is recalling certain 2022 Audi A6 Sedan, A4 Sedan, Q5, and Q5 Sportback vehicles. The semiconductor inside the engine control unit may short-circuit and cause an engine stall.

    Campaign #22V36800023/05/2022

    EQUIPMENT:ELECTRICAL:INFOTAINMENT:VIDEO (TOUCH)SCREEN/MONITOR/UNIT

    Volkswagen Group of America, Inc. (Audi) is recalling certain 2021-2022 AUDI A8, A6 Allroad, E-TRON Quattro, 2022 S3, RSQ8, RS7, RS6 Avant, Q8, Q7, Q3, E-TRON Sportback Quattro, S5 Cabriolet, E-TRON GT, S5 Sportback, A7, A6, A5 Sportback, A5 Cabriolet, A4, A4 Allroad, A3, S8, SQ7, SQ8, S6, and S4 vehicles. The infotainment main unit may become damaged internally when the vehicle is shut off, resulting in an inoperative rearview camera display the next time the vehicle is started. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 111, "Rear Visibility."

    Campaign #22V80600026/10/2022

    ELECTRICAL SYSTEM

    Volkswagen Group of America, Inc. (Audi) is recalling certain 2020-2022 Audi S7, S6 Sedan, A6 Allroad, 2021-2022 RS7, RS6 Avant, 2019-2022 A7, and A6 Sedan vehicles. Liquid spilled in the rear seat may penetrate and cause the gateway control module to shut down.

    Campaign #22V86100021/11/2022

    + 9 more recalls. Check all on NHTSA.gov

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    Frequently Asked Questions

    What are the most common Audi A6 problems?

    According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 1995-2025 Audi A6 has 23 documented issues. The most frequently reported are: 48V Belt Starter-Generator Warning and VIN-Specific Campaigns, Timing belt/tensioner failure causes catastrophic valve-piston contact, C5 A6 2.7T Low Boost or Smoke - Diagnose the System Before Buying a Turbo. Of these, 9 are rated critical and should be addressed promptly.

    Is the Audi A6 reliable?

    The 1995-2025 Audi A6 has 23 known issues compiled from NHTSA recalls, manufacturer TSBs, and owner forum reports. 9 issues are rated critical: 48V Belt Starter-Generator Warning and VIN-Specific Campaigns and Timing belt/tensioner failure causes catastrophic valve-piston contact and C5 A6 2.7T Low Boost or Smoke - Diagnose the System Before Buying a Turbo and Headlight-Switch Wiring Fire Recalls JC and JN and Tie-Rod Seal Failure Recalls 99V-248 and 00V-414 and 2006 A6 Multitronic 01J Delayed D/R Engagement - Check the Axial-Seal TSB and C5 A6 Bosch 5.3 ABS Warning or No Communication - Identify and Test Before Module Work and Gateway Control Module Liquid-Ingress Recall 90V2 (22V-861) and Timing Chain Tensioner Failure (3.2L V6 & 4.2L V8). Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.

    How much does it cost to fix common Audi A6 problems?

    Repair costs for known Audi A6 issues range from $0 to $12,000, depending on the specific problem and whether you choose DIY or professional repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

    What year Audi A6 is the most reliable?

    Reliability varies across model years of the Audi A6. Based on documented issues, problems are most commonly reported in earlier model years. Au7o recommends checking the specific known issues for your target year before purchasing, and having a pre-purchase inspection performed by a qualified mechanic. Our known issues database covers the 1995-2025 Audi A6 with 23 documented issues compiled from NHTSA recalls, manufacturer TSBs, and owner forum reports.

    What is the 2019-2025 Audi A6 48V Belt Starter-Generator Warning and VIN-Specific Campaigns?

    A 48V electrical-system warning on a mild-hybrid A6 is not repaired with an ordinary 12V battery, charger, alternator, or starter. Certain 2019-2020 2.0T mild-hybrid vehicles are covered by safety recall 27H2 or 20V-153 for moisture intrusion into the belt starter generator, whic… Severity: high.

    What is the 1995-1999 Audi A6 Timing belt/tensioner failure causes catastrophic valve-piston contact?

    The 2.8L V6 (both 12V AAH in the C4 1995-1997 and 30V AHA/ATQ in the C5 starting 1998) is an interference engine, so timing belt, tensioner, idler, or hydraulic damper failure between service intervals will allow the valves to strike the pistons, bending valves and sometimes crac… Repairs typically run $900-$4,500. Severity: high.

    What is the 2000-2002 Audi A6 C5 A6 2.7T Low Boost or Smoke - Diagnose the System Before Buying a Turbo?

    The 2000-2002 C5 A6 Quattro 2.7T APB uses two position-specific turbochargers plus wastegate control, N75 regulation, recirculation valves, vacuum plumbing, charge-air hoses/intercoolers, crankcase ventilation, and separate oil/coolant connections. Low boost, noise, or exhaust sm… Severity: high.

    What is the 1998-2004 Audi A6 Headlight-Switch Wiring Fire Recalls JC and JN?

    Audi recall 04V-133 (campaign JC) covers certain 1998-2004 A6 and S6 vehicles because the headlight-switch wiring harness can contact the driver's-side crossmember area, eventually shorting and creating a fire risk in the left dashboard. Audi later issued recall 06V-198 (campaign… Repairs typically run $0-$0. Severity: high.

    What is the 1998-1999 Audi A6 Tie-Rod Seal Failure Recalls 99V-248 and 00V-414?

    Certain 1998-1999 Audi A6 vehicles were included in safety recalls 99V-248 and 00V-414 for tie rods whose seals might not keep moisture and dust out of the swivel-bearing mechanism. Contamination can accelerate wear and create excessive play, reducing steering control. Clunking,… Repairs typically run $0-$0. Severity: high.

    What is the 2006 Audi A6 2006 A6 Multitronic 01J Delayed D/R Engagement - Check the Axial-Seal TSB?

    Audi TSB 2013280/4 addresses a specific loss-of-pressure condition in Multitronic transmissions produced from May 2005 through May 2006. The vehicle may not move or may engage Drive or Reverse only after a delay and increased engine speed; P1743/18151 may be stored. Audi attribut… Severity: high.

    What is the 1998-2001 Audi A6 C5 A6 Bosch 5.3 ABS Warning or No Communication - Identify and Test Before Module Work?

    Some 1998-2001 C5 A6 configurations use Bosch 5.3 brake electronics, but Audi documents several ABS/EDL, ASR, and ESP versions with engine- and transmission-specific coding. An ABS lamp, red brake warning, wheel-speed fault, or failure to communicate with address 03 does not by i… Severity: high.

    What is the 2019-2022 Audi A6 Gateway Control Module Liquid-Ingress Recall 90V2 (22V-861)?

    Certain 2019-2022 Audi A6 Sedan and 2020-2022 A6 allroad vehicles are included in safety recall 22V-861, Audi campaign 90V2. Liquid spilled on the rear seat can reach the gateway control module beneath the rear middle seat. If the module detects implausible signals or internal sh… Repairs typically run $0-$0. Severity: high.

    What is the 2005-2011 Audi A6 Timing Chain Tensioner Failure (3.2L V6 & 4.2L V8)?

    The C6 A6 with the 3.2L V6 and 4.2L V8 engines suffers from timing chain tensioner failures due to wear over time. Audi designates the chains and tensioners as "lifetime" parts requiring no maintenance, but they fail as early as 80,000-120,000 miles. The 3.2L engine has 4 chains,… Repairs typically run $3,000-$12,000. Severity: high.

    What is the 2005-2023 Audi A6 Water Pump and Thermostat Failure (Overheating)?

    Water pump failures are common across all A6 generations due to plastic impeller degradation and seal leaks. Audi uses plastic impellers that crack or disintegrate over time (typically 80,000-120,000 miles), causing coolant leaks and overheating. The water pump is often driven by… Repairs typically run $800-$1,500. Severity: medium.

    What is the 1998-2004 Audi A6 C5 Sunroof and Fresh-Air Plenum Drain Water Ingress?

    The federal Dewey settlement record identifies 1998-2005 Audi A6 C5 vehicles with the 4B platform code, including allroad, S, and RS versions, among vehicles alleged to be susceptible to passenger-compartment water ingress through sunroof drains or the fresh-air plenum. This page… Severity: medium.

    What is the 1998-2001 Audi A6 C5 A6 2.8L Rear-Engine Coolant Leak - Locate the Connection First?

    Audi repair literature for the C5 2.8L AHA engine identifies a rear coolant pipe and multiple sealed cooling-system connections. Owner reports on 2.8L AHA/ATQ cars also show why a leak at the rear of the engine cannot be assigned to one O-ring from symptoms alone: coolant can esc… Severity: medium.

    What is the 2000-2004 Audi A6 Front Suspension Multi-Link Control Arm and Tie-Rod Wear Causing Clunks and Tire Wear?

    The C5 A6 uses a multi-link aluminum front suspension with multiple upper and lower control arms whose ball joints and bushings commonly wear out, especially on rough roads or higher-mileage cars. Owners frequently report front-end clunking over bumps, wandering steering, vibrati… Repairs typically run $600-$1,800. Severity: medium.

    What is the 2012-2015 Audi A6 2012-2015 A6 ABS/ESP Warning With Engine Will Not Switch Off?

    Audi TSB 2037761/1 covers a specific situation in which a 2012-2015 A6 shows ABS/ESP warnings and the engine does not switch off with a normal press of START ENGINE STOP. The ignition system uses the ABS control unit's vehicle-speed signal to determine whether the car is stationa… Severity: medium.

    What is the 2019-2021 Audi A6 2019-2021 A6 3.0L Misfire Codes - Check ECM Software Before Mechanical Cleaning?

    For a 2019-2021 Audi A6 equipped with the 3.0L TFSI engine, the malfunction indicator lamp may illuminate with P0300 and one or more cylinder-specific P0301-P0306 codes. Audi's service information identifies an applicable ECM software-calibration condition and publishes model-yea… Severity: medium.

    What is the 2000-2004 Audi A6 2.7T Ignition Coil Pack Failure Causing Misfires and Flashing Check Engine Light?

    The 2.7T V6 used in A6 2.7T models is well known for ignition coil pack failures that cause sudden misfires, rough running, and loss of power. This issue was widespread across many early-2000s Audi/VW turbo models and generated numerous owner complaints and service actions. Failu… Repairs typically run $120-$500. Severity: medium.

    What is the 2019 Audi A6 2019 MIB2+ Lower MMI/HVAC Display Distortion or Flicker?

    Audi TSB 2053875/1 applies to 2019 A6 vehicles equipped with MIB2+. The documented condition is a flickering lower MMI/HVAC display or streaked colored horizontal lines. Audi attributes it to a hardware problem in the upper MMI screen that corrupts image data sent to the lower di… Severity: medium.

    What is the 2021-2022 Audi A6 2021-2022 A6 Virtual Cockpit Continuous Colored Pixel Line?

    Audi TSB 2064983/1 covers 2021-2022 A6 models equipped with Audi Virtual Cockpit Gen2+. A red, green, or blue continuous vertical line can appear through the instrument-cluster display; Audi identifies this as a hardware issue in the Virtual Cockpit. This is distinct from the old… Severity: low.

    What is the 2005-2023 Audi A6 Electrical Issues (Window Regulators, Door Locks, MMI)?

    The Audi A6 is prone to various electrical gremlins across all generations, including window regulator failures, door lock actuator failures, MMI/infotainment glitches, and battery drain issues. Window regulators fail due to weak plastic clips in the mechanism, causing windows to… Repairs typically run $100-$2,500. Severity: low.

    What is the 2018-2021 Audi A6 2018-2021 A6 Adaptive Suspension - Verify Compressor Pressure With a Physical Tester?

    Audi TSB 2062932/1 describes an informational diagnostic issue on 2018-2021 A6/A7 vehicles with adaptive suspension. During PDI or diagnosis, ODIS address 0074 may show accumulator or system pressure above 25 bar even though that is not the actual pressure; some J775 suspension-c… Severity: low.

    Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.

    Data compiled from NHTSA recalls, manufacturer TSBs, automotive forums, and AI-assisted research. No aggregated owner-report counts available for this vehicle yet.