2004 Audi A6 Reliability Report

NHTSA data as of Oct 15, 2026Published Oct 19, 2026

Good

Ranks 8th of 22 A6 years we score.

Owner complaints: 35; 1 is a recall notice
Per 10,000 cars: 15.8; 21,551 made for the U.S.
Vs the average car: 0.51×; same age, 1× is average
Serious outcomes: 12; crash, fire, injury, stall or tow
Recalls: 4
NHTSA crash rating: –

← 2003 A6 2005 A6 →

Should You Buy the 2004 Audi A6?

Yes, with the usual checks. Our reliability score for the 2004 Audi A6 is 77 out of 100, which rates Good. Owners reported about half as many problems as for the average car of the same age. It ranks 8th of the 22 A6 years we score.

The most reported problem is fuel tank or fuel lines (5 of 35 complaints). Owners also complain about tires and the fuel pump. 12 of the 35 complaints describe a serious outcome, such as a crash, a fire, an injury or stalling while driving.

It has 4 recalls. Audi also offers a warranty extension that may still apply, for a problem with the transmission. For comparison, the 2003 scores 69.

Before you buy, check that the recalls were done, ask an Audi dealer about warranty extension AWA-13-04 and get an independent inspection. The full checklist is at the end of this page.

Pros

Good reliability score of 77
About half the problems of the average car its age
No do-not-drive or park-outside recalls
1 Audi warranty extension may cover repairs

Cons

Fuel leak5 complaints
Tires: parts breaking or coming apart4 complaints
Fuel pump: stalling3 complaints

How the 2004 A6 Earned Its Score

Every model year starts at 100. Each part takes points away when this year has more problems than the average car of the same age. How we score

Score breakdown
Item	Vs average	Points lost
Starting score		100
Serious problems	0.49×	−11
Everyday problems	0.54×	−5
Problems in the last two years	Not counted	–
Recalls	1.1×	−7
Score		77

Problems in the last two years are not counted for the 2004 A6. If it were exactly average, its 21,551 cars would draw about 0.4 complaints in two years at this age, too few to compare. Their 30% moves to serious and everyday problems, which count for 80% of this score instead of 50%.

What Owners Report

We read all 35 complaints filed with NHTSA for the 2004 Audi A6, one by one, and grouped them by the problem they describe. The most reported problems come first.

Fuel leak
5 complaints (14%)
A leak and damage. Median mileage when it started: about 105,000 miles.
Tires: parts breaking or coming apart
4 complaints (11%)
Parts breaking or coming apart, damage and a leak. 1 of these 4 complaints describes a serious outcome.
Fuel pump: stalling
3 complaints (9%)
Stalling. All 3 describe a serious outcome, most often stalling or losing power while driving. Median mileage when it started: about 81,000 miles.
Seats: damage
3 complaints (9%)
Damage. Median mileage when it started: about 44,000 miles.
ABS: works on and off
2 complaints (6%)
Problems that come and go.
Brakes failure
2 complaints (6%)
A failure that needed a new part and loss of braking. 1 of these 2 complaints describes a serious outcome: a crash.
Frontal airbags failure
2 complaints (6%)
A failure.

Reported Once (14)

Show the 14 problems reported once

12V battery: parts breaking or coming apart
Brake calipers: overheating
Check engine light (cause not stated)
Engine: surging
Engine air intake: stalling
Exhaust or catalytic converter: a leak
Fuel injector: a leak
Headlights: stopped working
Fire (cause not stated)
Piston rings failure
Rearview camera: works on and off
Steering: vibration or shudder
Transmission: unusual noises
Wiring, fuses or body control module: a fire

How the 2004 Audi A6 Compares With Other Years

The other A6 years of the 5th generation (C5), 2000 to 2004, and the years just before and after it.

Year	Rating	Score	Vs average	Per 10k cars	Recalls	Most reported problem
2005	Good	72	0.84×	28.1	3	Parking brake: not releasing
2004 This year	Good	77	0.51×	15.8	4	Fuel leak
2003	Caution	69	0.95×	28.1	7	Fuel leak
2002	Caution	69	1.0×	34.1	4	Fuel leak
2001	Good	71	0.77×	26.8	7	Brakes: loss of braking
2000	Caution	67	1.2×	55.5	4	ABS failure

See every A6 year

2004 Audi A6 Recalls

Four recalls cover the 2004 Audi A6. The most recent was issued in May 2011: “Fuel Tank Rollover Valve.” A VIN check at NHTSA shows which are still open on a given car.

Fuel Tank Rollover Valve, May 2011
A fuel leak in the presence of an ignition source could lead to a vehicle fire.
NHTSA 11V267000 Owner letter (PDF)Issued May 3, 2011.
Fuel Tank Rollover Valve, April 2008
A fuel leak in the presence of an ignition source could lead to a vehicle fire.
NHTSA 08V157000 Owner letter (PDF)Issued Apr 8, 2008.
Crossmember Cover/Drivers Side Dash Fire
Audi S6 and S6 avant vehicles are all equipped with xenon low beam headlights and, therefore, are not longer affected by this recall. This condition could lead to overheating or fire.
NHTSA 06V198000 Owner letter (PDF)Issued Jun 5, 2006.
Vw/Drivers Side Dash Fire
A fire could originate in the left dashboard area.
NHTSA 04V133000 Owner letter (PDF)Issued Mar 18, 2004.

2004 Audi A6 Warranty Extensions and Programs

Audi has one warranty extension for the 2004 Audi A6, separate from its recalls. It is for a problem with the transmission. Whether one applies to a car depends on its VIN, which an Audi dealer can check.

Warranty extensionAudi AWA-13-04
CVT transmission and control module failures
The problem:
The bulletin names no symptom. Under a class action settlement, Audi extended the warranty on parts of the factory CVT transmission.
The fix:
An Audi dealer diagnoses and repairs or replaces the covered CVT parts. Which parts are covered depends on the model year.
Who qualifies:
Certain 2002 to 2006 A4 and A6 with the factory CVT. Control module: 2003 to 2006. Valve body: 2003 and 2004. Rest of the transmission: 2002 to 2004, only with proof of the owner's manual transmission maintenance.
Coverage:
10 years or 100,000 miles from the original in-service date, whichever comes first.
Audi's bulletin (PDF)

2004 Audi A6 NHTSA Investigations

NHTSA has opened one investigation that covers the 2004 Audi A6. It led to a recall.

Fuel leaking from the top of the fuel tank
Led to a recall
NHTSA looked into fuel leaking from the top of the tank on 2001-2005 Audi A6 Quattro and Allroad Quattro cars. It had 17 complaints since 2006. A material change in the rollover valve and an inflexible aluminum vent line could crack a valve fitting. Recall 08V-157 has Audi reinforce the valve with epoxy adhesive. NHTSA closed the investigation.
NHTSA PE08008 Opening report (PDF)Closing report (PDF)Jan 31, 2008 to May 30, 2008

Check Before You Buy

A checklist for the 2004 A6, from its four recalls, an Audi warranty extension that may still apply and the problems owners report most.

Confirm the Recalls Were Done

Ask the seller for proof that each of these recalls was repaired.

Fuel Tank Rollover Valve, May 2011 NHTSA 11V267000
Fuel Tank Rollover Valve, April 2008 NHTSA 08V157000
Crossmember Cover/Drivers Side Dash Fire NHTSA 06V198000
Vw/Drivers Side Dash Fire NHTSA 04V133000

Ask an Audi Dealer

Ask whether this warranty extension applies to this VIN, and whether the work was done.

AWA-13-04: CVT transmission and control module failures

On the Test Drive

Look for uneven tire wear and listen for clunks or humming that changes with speed.
Confirm any fuel pump recall was done. Hard starting or stalling is a warning sign.
Brake firmly from a moderate speed. A soft, hard or pulsing pedal, or a brake warning light, is a warning sign.

Ask the Seller

Ask whether any of these were ever repaired, and ask to see the receipts.

Fuel tank or fuel lines
Tires
Fuel pump
Also ask for the service records, especially oil changes.

Before You Pay

Get an independent pre-purchase inspection from a mechanic you choose.
Decode the VIN to confirm the model year, engine and trim.
Check the title for salvage, flood or rebuilt branding.

What to do next

All A6 Years →Best years and years to avoid, side by side.Compare With Other Years →Put up to four model years side by side.Find Warranty Extensions →Repairs Audi may still cover for this year.Decode a VIN →Confirm the exact year, engine and trim of a car.