Audi›A6/S6/Allroad›2004›Overview/audi/a6-s6-allroad/2004/base/

2004 Audi A6/S6/Allroad

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 2004 A6/S6/Allroad.

Body PASSENGER CARTransmission Automatic (variable gear ratios)

The 2004 Audi A6/S6/Allroad represents a generation of Audi's midsize luxury passenger car platform, featuring an automatic transmission with variable gear ratios and EPA fuel economy ratings of 18 city, 25 highway, and 21 combined miles per gallon; service intervals require 4.2 quarts of oil within a viscosity range of 5W-30 through 10W-30. With 35 total owner complaints logged against a backdrop of four manufacturer recalls, this model year sits within a period marked by moderate owner-reported concerns, the most prevalent involving the gasoline fuel system. For researchers evaluating long-term ownership costs and maintenance patterns, these complaint and recall figures suggest this generation warrants closer scrutiny of fuel system components during pre-purchase inspection.

Quick specs

Fluid capacities, tune-up values and fuel economy at a glance.

Engine oil capacity4.2 qtOEM · verified

Engine oil type5W-30 / 5W-40 / 10W-30 APIOEM · verified

Lug nut torque89 ft-lbsOEM · verified

EPA fuel economy18/25/21 mpgEPA · verified

Fitment & sizes

Replacement part sizes and factory part numbers — battery, bulbs, filters and belts.

From the factory this vehicle uses a BCI 49 · 850 CCA battery, OE oil filter 078115561J. Note the factory serpentine belt is now discontinued — plan on a superseded or quality aftermarket equivalent, which the part pages below list where known. Each part links to every other vehicle that shares it, so a part you already stock may fit more of your fleet than you'd expect.

Battery groupBCI 49 · 850 CCAOEM · verified

Tail / brake / turnTURNOEM · verified

Tire size225-55R17OEM · verified

OE service part numbers OEM · verified

Engine oil filter	078115561J
Engine air filter	058133843
Fuel filter	1H0201511A
Spark plug	101905611
Front wiper blades	4B1955425C
Serpentine belt	078903137BJ discontinued
Thermostat	06B121119C alt 06C121111E
Cabin air filter	4B0819439C

Full specifications

Engine, drivetrain, dimensions and economy.

Engine & drivetrain NHTSA vPIC

Transmission

Automatic (variable gear ratios)

Ratings & economy EPA / vPIC

EPA city / highway / combined	18 / 25 / 21 mpg
Drivetrain	Front-Wheel Drive
Passenger volume	98 cu ft
Cargo volume	15 cu ft
Recommended fuel	Premium Gasoline

Service quick specs OEM factory data

Capacities, torques and tune-up values from the factory service manual.

This engine holds 4.2 qt of 5W-30 / 5W-40 / 10W-30 API engine oil, SYNTHETIC · 75W-90 · GL-4 · GL-5 in the differential, DOT 4 brake fluid. Torque lug nuts to 89 ft-lbs. The firing order is 1-5-4-8-6-3-7-2. Note the cylinder-head bolts finish on a torque angle (torque-to-yield) — they stretch permanently and should be replaced, not reused, during any head service.

Lubricants & capacities

Automatic Transmission Fluid	Audi part number G060162A2
Automatic Transmission Fluid Capacity	8.5-11.0
Brake Fluid	DOT 4
Differential Gear Oil Capacity	1.7 Pints
Differential Gear Oil	SYNTHETIC · 75W-90 · GL-4 · GL-5
Differential Gear Oil Capacity	3.2 Pints
Engine Oil Capacity	4.2 qt
Engine Oil Capacity	6.9 qt

Engine torques

Camshaft Bearing/Carrier Cap Bolts or Studs	7 ft-lbs
Camshaft Bearing/Carrier Cap Bolts or Studs	18 ft-lbs
Camshaft Bearing/Carrier Cap Bolts or Studs	11 ft-lbs
Intake Manifold to Engine Bolts	7 ft-lbs
Exhaust Manifold to Cylinder Head Bolts	18 ft-lbs
Intake Manifold to Engine Bolts	7 ft-lbs
Exhaust Manifold to Cylinder Head Bolts	18 ft-lbs
Intake Manifold to Engine Bolts	7 ft-lbs

Chassis torques

Lug Nuts	89 ft-lbs
Transfer Case Fill Plug	26.0 ft-lbs
Transfer Case Drain Plug	26.0 ft-lbs
Rear Wheel Hub	148 ft-lbs

Ignition

Cylinder Firing Order	1-4-3-6-2-5
Cylinder Firing Order	1-5-4-8-6-3-7-2
Curb Idle Speed (No Load)	700 rpm
Curb Idle Speed Variance (No Load)	50 rpm
Curb Idle Speed (No Load)	750 rpm
Curb Idle Speed Variance (No Load)	50 rpm
Ignition Coil Primary Resistance	0.3-0.5 ohms
Spark Plug Manufacturer	VW

Battery & A/C

Refrigerant	R134a
Standard BCI Group Number	49
Standard BCI Cranking Performance	850 cca
Optional BCI Group Number	94R
Optional BCI Cranking Performance	640 cca
Optional BCI Group Number	49
Optional BCI Cranking Performance	760 cca
Standard BCI Group Number	48

Service checks

Pressure Test	14.5 psi
Radiator Cap Pressure Relief	20-23 psi
Thermostat Opening Temperature	188 °F
Pressure Test	14.5 psi
Radiator Cap Pressure Relief	20-23 psi
Thermostat Opening Temperature	188 °F
Regulated Fuel System Pressure (Without Vacuum)	55.0-61.0 psi
Regulated Fuel System Pressure (With Vacuum)	46.0-5.0 psi

Brakes

Torque to Knuckle	89 ft-lbs / 95 ft-lbs
Torque Caliper to Bracket	26 ft-lbs / 18 ft-lbs
Torque to Knuckle	89 ft-lbs / 95 ft-lbs
Torque Caliper to Bracket	26 ft-lbs / 18 ft-lbs
Rotor Nominal Thickness From	1.181 in / 0.394 in / 0.984 in / 0.866 in
Rotor Nominal Thickness To	1.181 in / 0.394 in / 0.984 in / 0.866 in
Rotor Discard at or Under	1.102 in / 0.315 in / 0.906 in / 0.787 in
Rotor Nominal Thickness From	1.181 in / 0.394 in / 0.984 in / 0.866 in

Multi-step torque procedures OEM · verified

Connecting Rod (Large End) Bearings — tightening sequence 1 stages

22 ft. lbs., Step 2: 90

22 ft. lbs

Connecting Rod (Large End) Bearings — tightening sequence 1 stages

22 ft. lbs., Step 2: 90

22 ft. lbs

Cylinder Head — tightening sequence 2 stages

1	29.5 ft. lbs.	29.5 ft. lbs
2	180 degrees	180 degrees

Cylinder Head — tightening sequence 2 stages

1	44.0 ft. lbs.	44 ft. lbs
2	180 degrees	180 degrees

Flex or Driveplate Bolts — tightening sequence 1 stages

44 ft. lbs., Step 2: 90

44 ft. lbs

Engine Flywheel Bolts — tightening sequence 1 stages

44 ft. lbs., Step 2: 180

44 ft. lbs

Engine Flywheel Bolts — tightening sequence 1 stages

44 ft. lbs., Step 2: 90

44 ft. lbs

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the engine oil and filter every 5,000 mi.

At 5,000 mi	Brake System (inspect) · Headlamp Washer Nozzle (inspect) · Headlamp Washer System (inspect fluid level) · Tire & Wheel Assembly (inspect) · Windshield Washer System (inspect)
Every 5,000 mi	Engine Oil (drain & refill) · Engine Oil Filter (replace) · Tire & Wheel Assembly (rotate) · Windshield Washer System (inspect fluid level)
Every 10,000 mi	Brake System (inspect) · Headlamp Washer Nozzle (inspect) · Headlamp Washer System (inspect fluid level) · Tire & Wheel Assembly (inspect) · Windshield Washer System (inspect)
At 15,000 mi	Accessory Drive Belt (inspect) · Battery (inspect electrolyte level) · CV Joint Boot (inspect) · Cabin Air Filter (replace) · Door Hinge (lubricate) · Door Stop (lubricate)
Every 20,000 mi	Accessory Drive Belt (inspect) · Battery (inspect electrolyte level) · CV Joint Boot (inspect) · Cabin Air Filter (replace) · Door Hinge (lubricate) · Door Stop (lubricate)
At 35,000 mi	Engine Air Filter Element (replace) · Engine Air Filter Housing (clean) · Power Steering System (inspect fluid level)
Every 35,000 mi	Air Conditioning Condenser (clean) · Radiator (clean) · Timing Belt (replace) · Timing Belt Idler Pulley (replace)
Every 40,000 mi	Air Conditioning Evaporator Case Drain (inspect) · Engine Air Filter Element (replace) · Engine Air Filter Housing (clean) · Power Steering System (inspect fluid level) · Sunroof Assembly (inspect) · Transmission Assembly (drain & refill)
Every 75,000 mi	Accessory Drive Belt (inspect) · Drive Belt (replace) · Timing Belt Tensioner (replace)

Reliability & federal safety record

Owner-reported issues, recalls, investigations and service bulletins on record with NHTSA — an unfiltered look at what owners actually experience.

Owner complaints about the 2004 Audi A6/S6/Allroad top in one area — the fuel system, gasoline, 4 of 35 reports (11%), well ahead of the next concern. That matters, because the fuel system, gasoline are also the target of recalls 11V-267 and 08V-157 on this vehicle — so the single most useful check before buying or servicing one is confirming they were actually performed. 1 of the reports describe a crash and 2 a fire — a small share of the total, but worth weighing against the fuel system, gasoline pattern above. These are tallies of what owners actually reported to the federal government, not an editorial score — and higher-selling models naturally rack up more reports.

Open recalls

NHTSA campaigns

151

Service bulletins

Manufacturer communications

ODI investigations

Office of Defects Investigation

Owner complaints

1 involved a crash · 2 a fire

NHTSA crash-test rating federal NCAP · out of 5 stars

Rollover★★★★★

Owner complaints filed with NHTSA, by component

All 35 complaints on record, top 8 components.

Fuel System, Gasoline4

Fuel/Propulsion System3

Electrical System3

Seats3

Engine & Engine Cooling2

Exterior Lighting2

Air Bags2

Wheels2

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 2 of 4 campaigns on record for this vehicle.

11V267000Fuel System, Other:Storage:Tank AssemblyReported 03/05/2011

VOLKSWAGEN IS RECALLING CERTAIN MODEL YEAR 2001-2004 AUDI A6, MODEL YEAR 2002-2003 S6 AND MODEL YEAR 2003 RS6 VEHICLES EQUIPPED WITH 4.2L ENGINES AND MANUFACTURED FROM JUNE 19, 2001, THROUGH JUNE 8, 2004. THE AGING OF… Remedy: DEALERS WILL REINFORCE THE NIPPLE ON THE ROLLOVER VALVE TO PREVENT LEAKAGE OR REPAIR THE CRACKING AT THE NIPPLE. THE RECALL IS EXPECTED TO BEGIN DURING JUNE 2011. OWNERS MAY…

08V157000Fuel System, Gasoline:Storage:Tank AssemblyReported 08/04/2008

VOLKSWAGEN IS RECALLING 68,240 MY 2001-2004 AUDI A6 QUATTRO VEHICLES EQUIPPED WITH 2.7L, 2.8L, OR 3.0L ENGINES AND MY 2001-2005 ALLROAD QUATTRO VEHICLES EQUIPPED WITH 2.7L OR 4.2L ENGINES. THE AGING OF THE PLASTIC… Remedy: DEALERS WILL REINFORCE THE NIPPLE ON THE ROLLOVER VALVE TO PREVENT LEAKAGE OR REPAIR THE CRACKING AT THE NIPPLE. THE RECALL BEGAN ON JUNE 27, 2008. OWNERS MAY CONTACT AUDI AT…

Technical service bulletins NHTSA · verified

Showing 5 of 151 bulletins on record with NHTSA.

Bulletin	Date	Component	Summary
A0023742052680_4	2023-10-04	Equipment	This bulletin provides information on the additional reporting requirements for safety…
SM 48-2022	2022-06-15	Equipment	This special notice is to inform dealers to return the parts listed if it meets the…
A0021482021205_6	2021-06-25	Structure	This informational bulletin explains how to order replacement VIN plates, Safety…
A4021242016453_4	2021-04-21	Suspension	This bulletin contains instructions for determining if bushings need to be replaced.
A0020362002047_1	2020-04-16	Equipment	This information bulletin contains instructions for technicans on how to ensure their TAC…

Common OBD-II trouble codes

The most common OBD-II codes for this vehicle's emissions system. These are standardized SAE J2012 definitions, not vehicle-specific fault reports.

P0420

Catalyst system efficiency below threshold — Bank 1

P0300

Random / multiple cylinder misfire detected

P0171

System too lean — Bank 1

P0455

Evaporative emission system leak detected — large leak

P0128

Coolant thermostat below regulating temperature

P0442

Evaporative emission system leak detected — small leak

VIN tools

Decode factory build data for a specific vehicle by VIN.

VIN

Decode a VIN to confirm the transmission and build data for a specific A6/S6/Allroad. OEM

Build data

Plant, GVWR class, engine and body data for any 17-character VIN.

Recalls

Check open recall campaigns against a specific vehicle by VIN.

Vehicles with shared specs

Find every vehicle that shares this one's battery, bulbs, oil capacity, platform or parts.

Group 49 battery Vehicles taking 4.2 qt Engine oil filter 078115561J Engine air filter 058133843 Fuel filter 1H0201511A Spark plug 101905611

Reference guides

Cross-vehicle references for the kinds of data on this page.

Vehicle recalls & TSBs OBD-II trouble codes Torque specifications Maintenance schedules Fluid capacities & specs

Frequently asked

How much oil does the 2004 A6/S6/Allroad take?

4.2 qt of ENERGY CONSERVING OILS: 5W-30, 5W-40, 10W-30 OR 10W-40 API SL, EXCEPT ENGERGY CONSERVING OILS: 5W-50, 10W-50, OR 10W-60 API SL, per the factory manual.

Does the 2004 A6/S6/Allroad have open recalls?

NHTSA lists 4 recall campaign(s) for this model year. Check your specific vehicle by VIN.

What gas mileage does the A6/S6/Allroad get?

EPA figures are 18 city / 25 highway / 21 combined mpg.