The 2004 Audi A6 has no open NHTSA recalls. Owners report 6 recurring issue clusters, led by “Fuel tank and rollover valve leak with gasoline odor.” Audi follows the VW Group Longlife service rhythm: oil and minor service every 10,000 miles or 12 months, whichever comes first, using oil that meets VW 502 00 / 504 00 (or 508 00 for newer 0W-20 engines) — generic synthetic does not qualify. S tronic dual-clutch gearboxes need fluid service every 40,000 miles despite 'lifetime fill' claims. Fully electric models (e-tron, e-tron GT) skip oil service entirely but keep brake-fluid, cabin-filter, and coolant-circuit intervals.
No open recalls on file. NHTSA lists no unrepaired safety recalls for this year, make and model. A recall can be issued at any time, and a specific car can still have one open — check yours by VIN at nhtsa.gov/recalls.
What drivers and federal regulators have officially reported about the 2004 Audi A6.
FUEL SYSTEM, GASOLINE
5 NHTSA complaints · 2009-11 → 2018-12
“THE CONTACT STATED THAT WHEN REFUELING THE VEHICLE OVER THE THREE QUARTER CAPACITY LEVEL, A SUBSTANTIAL AMOUNT OF FUEL WOULD LEAK UNDERNEATH THE VEHICLE NEAR THE EXHAUST PIPE”
“WHEN DRIVING HE SMELLED A STRONG ODOR OF GASOLINE INSIDE OF THE VEHICLE”
“THE CONTACT STATED THAT WHILE STARTING THE VEHICLE, A STRONG ODOR OF GASOLINE EMITTED INSIDE AND AROUND THE VEHICLE”
TIRES
4 NHTSA complaints · 2004-04 → 2006-06
“WITHIN THE FIRST 4,000 MILES, ALL UNDER NORMAL DRIVING CONDITIONS, A LARGE BULGE DEVELOPED ON THE SIDEWALL OF ONE OF THE REAR TIRES”
“CONSUMER HAS EXPERIENCED 4 TIRE BLOW OUTS WITHT EH CONTINENTAL TIRE EQUIPMENT”
“DURING THE FIRST 18 MONTHS, I HAVE EXPERIENCED 4 FLAT TIRES ON MY AUDI A6 2.7T S LINE”
ELECTRONIC STABILITY CONTROL (ESC), SERVICE BRAKES
2 NHTSA complaints · 2015-02 → 2023-12
“- ABS Module has intermittent failures, available for inspection - Anti-lock brakes will not work - Yes, the problem reoccurs and the module loses power and then errors out - Others - VCDS - ABS lights come on and BRAKE light stays illuminated”
“WITH THE ELEC STABILITY CONTROL BEING INTERMITTENT THIS IS BEING CAUSED BY THE ABS MODULE GOING BAD/INTERMITTENT THE BRAKE PEDAL PRESSURE CHANGES”
FUEL SYSTEM, GASOLINE
3 NHTSA complaints · 2010-01 → 2011-02
“VEHICLE WAS TOWED TO REPAIR SHOP WHERE IT WAS DETERMINED THAT THE FUEL PUMP HAD FAILED”
“CAR'S ENGINE STOPPED WHILE AT A RED LIGHT”
“THE CAR SUDDENLY LOST ALL ENGINE POWER AND STALLED ON THE HIGHWAY”
SEATS
3 NHTSA complaints · 2009-02 → 2010-04
“THEY SMELLED SOMETHING BURNING AND IT TURNED OUT IT WAS THE HEATED SEAT”
“THE CAR WAS EXAMINED BY AN AUDI DEALER WHO SAID THE SWITCH HAD SHORTED OUT AND THE HEATING ELEMENT BURNT THE SEAT”
“I REPORTED THAT MY BACK PASSENGER SEAT HAD ALMOST CAUGHT FIRE, AND WAS BURNT”
AIR BAGS
2 NHTSA complaints · 2009-12 → 2010-01
“PASSENGER AIR BAG FAILURE 2004 AUDI A-6”
“MY AUDI DEALER INFORMED ME OF A FAILURE IN THE PASSENGER SIDE AIRBAG AND IT HAD TO BE REPLACED AT A COST OF $931.99, I HAVE OWNED THIS CAR SINCE NEW AND IT IS ACCIDENT FEE”
Issues on other model years
Source: NHTSA Office of Defects Investigation (ODI). Complaint data refreshed Sep 20, 2026. Investigation data refreshed Sep 20, 2026.
We display NHTSA's record with attribution; we don't editorialize on what these complaints mean for any specific vehicle.
Critical for safety and preventing major damage
Replace oil and filter every 10,000 miles or 12 months with VW 502 00 / 504 00 / 508 00 spec oil. S and RS models driven hard: many owners shorten to 5,000-7,500 miles. Wrong-spec oil is the leading cause of TFSI timing-chain tensioner and PCV problems.
Estimated cost — typical U.S. ranges
Dealer
~$120–$160
Shop
~$85–$115
DIY
~$25–$55
Full synthetic costs more than conventional. 5-quart 0W-20 + filter is the typical bill.
Rotate every 10,000 miles with the oil service. quattro models: keep all four tires within 4/32" of each other — mismatched wear stresses the center differential.
Estimated cost — typical U.S. ranges
Dealer
~$85
Shop
~$60
DIY
Free
Often free at the shop where you bought the tires — worth asking before paying.
Inspect pads, rotors, and wear sensors every 10,000 miles. Audi uses electronic pad-wear sensors on most models — replace the sensor with the pads.
Estimated cost — typical U.S. ranges
Dealer
~$85
Shop
~$60
DIY
Free
Most shops do this free as a courtesy with any service. Don't pay separately if you can avoid it.
Replace DOT 4 brake fluid every 2 years regardless of mileage — Audi's published schedule is time-based because the fluid absorbs moisture.
Estimated cost — typical U.S. ranges
Dealer
~$180–$200
Shop
~$125–$140
DIY
~$10–$25
DOT 3 or 4 — match the cap. Vacuum bleeders make this a one-person DIY.
S tronic (DSG) gearboxes on A3/S3/RS 3, Q3, TT, and many A5/Q5 models: replace fluid and filter every 40,000 miles with the VW Group-spec fluid for your gearbox code. Skipping this service is the most common cause of mechatronic failure.
Estimated cost — typical U.S. ranges
Dealer
~$470–$640
Shop
~$330–$450
DIY
Pro only
VW/Audi DSG service needs a fluid-fill procedure at a specific temperature — shop equipment territory.
Keeps your vehicle running smoothly and efficiently
A3/S3/RS 3, Q3, and TT use a Haldex-style rear coupling: replace its fluid roughly every 40,000 miles (some model years specify sooner — check your manual). Longitudinal quattro (A5-A8, Q5, Q8) has no coupling service; see differential fluid instead.
Estimated cost — typical U.S. ranges
Dealer
~$220–$290
Shop
~$155–$205
DIY
~$40–$90
VW/Audi/Volvo AWD coupling — specific fluid required. Filter usually swapped at the same time.
TFSI turbo engines: new plugs every 40,000 miles. RS models with the 2.5 TFSI five-cylinder: consider 30,000 miles under track or hard street use.
Estimated cost — typical U.S. ranges
Dealer
~$285–$390
Shop
~$200–$275
DIY
~$25–$100
Iridium plugs cost more but last 100k+ miles. V6/V8 access varies wildly — some are tough.
Replace every 40,000 miles; inspect at 20,000 on turbocharged engines — a clogged filter shows up as sluggish boost response first.
Estimated cost — typical U.S. ranges
Dealer
~$60–$95
Shop
~$45–$70
DIY
~$15–$40
5-minute job on most cars; the airbox lid usually has clips, no tools needed.
2.0 TFSI (EA888) engines before roughly 2013 had timing-chain tensioner failures — have the tensioner revision checked by 80,000 miles on earlier cars. Later engines carry the updated design with no scheduled service.
Estimated cost — typical U.S. ranges
Dealer
~$85
Shop
~$60
DIY
Pro only
Timing chains are normally lifetime. Listen for rattle on cold start — that's the actionable signal. Replacement is major work, quote separately.
Extends the life of your vehicle and improves comfort
Q5, Q8, and A5-A8 quattro: independent Audi specialists recommend front/rear differential fluid service around 60,000 miles even where Audi lists it as lifetime fill.
Estimated cost — typical U.S. ranges
Dealer
~$150–$195
Shop
~$105–$135
DIY
~$20–$50
Drain plug + fill plug — straightforward DIY. AWD vehicles have two; budget for both.
Replace the cabin air filter every 20,000 miles or 2 years. Audi specifies an activated-carbon filter on most models.
Estimated cost — typical U.S. ranges
Dealer
~$60–$95
Shop
~$45–$70
DIY
~$15–$40
Usually behind the glovebox. Shops charge labor for a 10-minute job — easy DIY win.
Audi coolant is labeled lifetime fill. Independent VW/Audi specialists recommend a refresh around 5 years or 100,000 miles to protect the water pump and thermostat housing — and only with the correct pink/lilac VW Group coolant.
Estimated cost — typical U.S. ranges
Dealer
~$285–$330
Shop
~$200–$235
DIY
~$25–$60
Use the manufacturer-specified coolant — wrong color/chemistry can damage the cooling system.
Occupant deaths in fatal crashes (FARS)
19 crashes 1990–2024
How the 19 occupant deaths break down
14
driver deaths
5
passenger deaths
19
occupant deaths
Crash years covered: 1990–2024 This model year first appears in 2004 crashes. Older models have had more years on the road to appear in these crashes, so a higher count here does not by itself mean a vehicle is less safe.
FARS counts every occupant death in a fatal crash, whatever the cause — it does not mean the vehicle was at fault or defective. Counts are not adjusted for how many of each vehicle are on the road. How to read this number
FARS 2024 data is an annual report file. NHTSA revises these records when the final file is published, so this count can change.
Every vehicle has exactly one driver seat, so driver deaths line up fairly when you compare one model to another. Occupant deaths include passengers, so a three row SUV can show a higher number than a two seat car simply because it carries more people.
Both figures are plain counts, not rates. A rate would need to know how many of each vehicle are on the road, and that registration data is not public, so we do not publish rates or scores of any kind.
IIHS publishes driver death rates using this same driver only idea, paired with a registered vehicle years denominator we do not have. Their rates and these counts answer different questions, so do not read either number here as a safety rating.
Owner-reported problem signals
Separate from the federal fatality data above: complaints owners filed with NHTSA about this year and model. These are reports of problems, unverified, and are counted here only as signals.
1
complaints mentioning a crash
2
complaints mentioning a fire
Typical U.S. ranges. Actual quotes vary by shop, parts choice, and vehicle condition.
How we estimate: Dealer = OEM parts × 1.4 + labor × $165/hr. Shop = parts + labor × $115/hr. DIY = parts only.
This maintenance schedule for the 2004 Audi A6 reflects Audi's published service intervals and the Audi Service Interval Display system. Your actual service needs may vary based on driving conditions, climate, and vehicle usage. Always consult your owner's manual for model-specific recommendations.