Au7o mascotAu7o
Known IssuesTest Hub demo
  1. Au7o
  2. /
  3. Known Issues
  4. /
  5. Audi
  6. /
  7. A8
Audi · Known Issues

1999 Audi A8 Problems: 7 Known Issues

1999 model year · NHTSA recalls, manufacturer TSBs, and owner forum reports · Updated September 2026

Share:@au7o.io

1999 · All trims · All engines

Choose the year and equipment for your written issues and visual request.

Known IssuesMotorcycle IssuesDTC LookupDrivePricingAboutTermsPrivacyCookiesConsentData rightsCopyrightFeedback
Share:@au7o.io

Vehicle data and repair guidance on this site are compiled with AI assistance and may contain errors. Always verify with your service manual or a qualified mechanic.

Data protection representation

DataRep representative in the United KingdomDataRep representative in the European Union
Au7o · 2026
Built for DIY mechanics. Privacy-first.
Explore free Hub demo
No email neededHow interest is saved

Interest applies to the selected vehicle and configuration; it is not a reservation. Voting stores a first-party identifier for up to 180 days to prevent repeat votes. No account or email is needed. Clearing cookies or using another device may count separately. Privacy

Visual coming soon

Your interest helps us choose what to build next.

Visual Known Issues · Coming soon

$4.99/month plus taxes at launch · No payment today

Preview the XT6 example
Issue summary

According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 1999 Audi A8 has 7 documented known issues, with 3 rated critical. The most serious are D2 A8 4.2 V8 Timing Belt — Interval Retroactively Cut from 105k to 75k Miles (Interference Engine) ($1,500-$3,000 repair), 1998-1999 A8 Takata NADI Driver-Airbag Inflator Recall 69BT (20V056/22V471) and Bosch 5.3 ABS Control Module Internal Failure (EBCM) ($200-$600 repair). Across all issues with published estimates, repair costs range from $30 to $3,000. DIY maintenance guides at au7o.io.

In This Article

  • A8 Engine1
  • A8 Safety/Recalls1
  • A8 Brakes1
  • A8 Steering1
  • A8 Exterior1
  • A8 Emissions1
  • A8 Electrical1
  • Recalls5
  • FAQ
Get Started
Back to top

In This Article

  • Engine1
  • Safety/Recalls1
  • Brakes1
  • Steering1
  • Exterior1
  • Emissions1
  • Electrical1
  • Recalls5
  • FAQ

All 7 Known Issues

Filter:
ALL YEARS20252024202320222021202020192018201720162015201420132012201120102009200820072006200520042003200220012000199919981997199619951994

When Issues Typically Appear

Secondary Air Injection P0410/P0411 — Cracked Vacuum Lines, Stuck Combi Valves, Carbon-Clogged Head Ports
70K-180K
D2 A8 4.2 V8 Timing Belt — Interval Retroactively Cut from 105k to 75k Miles (Interference Engine)
75K-105K
Bosch 5.3 ABS Control Module Internal Failure (EBCM)
80K-150K
Pentosin CHF11S hydraulic system leaks (power steering pump, rack, hoses)
80K-180K
Instrument cluster LCD pixel fade / dead pixels on VDO display
80K-200K
050K100K150K200K mi

On the 1997-2003 Audi A8, the D2 A8 4.2L V8 (both the early 32-valve ABZ and the later 40-valve AUX/AWN/AKB) is an interference engine driven by a rubber timing belt. The original published interval was 105K miles on the C5 and D2 4.2, until Audi retroactively changed it to 75,000 miles. Many original-owner cars went well past 100k on the factory belt, and high-mileage examples are commonly bought with no timing belt service history. Around the timing belt service interval (75,000 miles), due to age the integrity of the tensioner(s), damper, water pump, and other seals and o-rings are at the end or very near the end of their service life, and some individuals make the mistake of only replacing the timing belt, only for it to fail 10,000-20,000 miles later due to tensioner, idler bearing, or water pump failure. Belt or tensioner failure on this engine bends valves and is typically a total-loss event for an older A8.

Common Symptoms

  • No symptoms before failure (silent killer)
  • Possible faint tensioner whine at idle late in belt life
  • Coolant weep at water pump if pump is original
  • Engine no-start / no-compression after failure

How to Fix

Procedure: pull the front off / put car in service position, take it apart, lock the cams and R&R the belt + water pump + thermostat and anything else worn or suspicious — consider doing valve cover gaskets and chain tensioner seals too, those seals would be slightly easier to get to while in the middle of the big service. A cam-lock bar is not totally critical, but definitely makes it easier and safer. A full kit (belt, tensioner, damper, idler rollers, water pump, thermostat, accessory belts) should be installed together; budget $1,500–$3,000 with labor at an independent Audi specialist. Replace at 75,000 miles OR 5–6 years, whichever comes first, regardless of what the original owner's book says.

Typical repair cost:$1,500 - $3,000

Research This Issue

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

On the 1998-1999 Audi A8, certain 1998-1999 Audi A8 vehicles may contain a Takata non-azide driver inflator that can absorb moisture and deploy improperly. NHTSA 20V056 originally listed the 1999 A8 branch, Audi 69BT campaign material lists 1998-1999 A8 vehicles, and NHTSA 22V471 corrects the filing to add the 1998 A8 population. Eligibility remains VIN-specific because the ranges are non-sequential and the vehicle is checked for the affected inflator.

How to Fix

Check the VIN for open Audi campaign 69BT / NHTSA 20V056 or its 22V471 correction. If open, an authorized Audi dealer checks the installed inflator and replaces an affected driver-airbag inflator with an alternative inflator free of charge. Do not disturb an airbag module yourself.

Research This Issue

GoogleRedditYouTubeNHTSA
NHTSA Verified
High ConfidenceVerifiedReviewed Jul 2026

On the 1997-2003 Audi A8, the Bosch 5.3 ABS/EBCM control module mounted to the side of the hydraulic pump unit suffers from internal solder joint and fine aluminum bond-wire fatigue, causing intermittent then permanent loss of ABS function. The Audi ABS pump & module system has been a very common failure for a long time, and the problem usually starts with the ABS light coming on intermittently but after a while becomes constant. Failed Bosch 5.3 control modules are extremely common in 2000-era Audis. On D2 A8/S8 cars, drivers typically see simultaneous ABS and red brake warning lights with three beeps at startup, and communication with the controller can drop out entirely (Link Error in VAG-COM). The ABS 5.3 system was introduced mid-1997 on the D2 platform; note that the 2002+ S8 reverted to a 5.0-based system, so verify the module on the car before ordering a repair.

Common Symptoms

  • ABS warning light on (often steady yellow)
  • Red brake warning light on simultaneously
  • Three beeps at startup
  • Intermittent fault that becomes permanent
  • No communication / Link Error with ABS controller (03) via VAG-COM
  • Failed state safety/emissions inspection

How to Fix

To confirm that the module is the problem, scan the ABS system with a VAG scan tool (factory scanner or VAG-COM/VCDS) — OBD-II generic scanners will not read ABS codes, and if you get a 'Link Error' / no communication with controller 03 (ABS Brakes), the module is almost certainly the cause. Rather than buying a new unit (largely NLA from Audi), the EBCM can be unbolted from the hydraulic block and sent out for rebuild. Only the electronic part of the ABS pump is normally needed — it is attached to the side of the pump with six torx screws and can be removed by first removing the passenger side front wheel and the inner wheel arch plastic liner, then unbolting the washer bottle and moving it out of the way. Repair services (Module Master, XeMODeX, UpFix, ECU Testing) keep coding/adaptations intact so the rebuilt module is plug-and-play with no programming required.

Typical repair cost:$200 - $600

Research This Issue

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

On the 1997-2003 Audi A8, the D2 A8's hydraulic system uses Pentosin mineral oil shared between the power steering pump, ZF rack with Servotronic module, and (on non-NA self-leveling cars) the rear shock accumulators. Owners report leaks in the middle of the pump where the two-piece housing is bolted together, often diagnosed with UV dye. Whining on cold start, low fluid in the trunk-mounted reservoir, and visible Pentosin (green) under the engine are classic signs. The dash brake warning light can also illuminate if the Pentosin reservoir is low or the hydraulic brake booster system is low on pressure, since the same fluid feeds the brake servo on these cars.

Common Symptoms

  • power steering whine on cold start
  • Pentosin fluid puddles under engine
  • low fluid in trunk reservoir
  • heavy steering when fluid is low
  • brake warning light when reservoir empty

How to Fix

Inspect the ZF tandem pump, rack pinion seal, and high-pressure lines with the engine running. A ZF rebuilt pump is around $280 in parts plus ~$350 labor and typically eliminates cold-start whine. Always refill with Pentosin CHF 11S (green) — never ATF, which destroys seals. When replacing the rack, also replace the Servotronic fluid strainer and o-rings on the nipple. Bleed by raising the front wheels off the ground and briefly starting the engine per Bentley procedure until air clears.

Typical repair cost:$400 - $2,500

Research This Issue

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

On the 1994-2002 Audi A8, factory-fitted options included halogen, D2S/H7 single-xenon, and D2R/H7 single-xenon headlights manufactured by Bosch (Automotive Lighting); the halogen H7 reflectors lose their reflective layer as it peels off from bulb heat and ageing, and the single-xenon 2.5-inch projectors are known to lose their reflective layer until they go black inside, causing dangerously low light output. On the 'Xenon Plus' headlights, a plastic diffuser sits right in front of the xenon lamp; heat and light intensity yellow the diffuser and cause micro-cracks that scatter the beam, and this diffuser is not a replaceable part and nothing can restore it. Drivers notice progressively dim night-time lighting and a cloudy/milky appearance to the projector lens.

Common Symptoms

  • dim headlights at night
  • yellowed or milky projector lens
  • black/burnt-looking reflector bowl behind the lens
  • uneven or scattered beam pattern

How to Fix

Open the headlight housing (clipped, not glued on the D2 — relatively easy) and inspect the projector reflector bowl. The existing projector can be removed through the rear bulb access port and replaced with an upgraded bi-xenon projector and bracket; the original screws are prone to breaking, in which case the headlight must be opened (the lens is only clipped in place) and the broken bolts drilled out. Aftermarket bi-xenon retrofit kits (Retrofitlab, Morimoto) using D2S bulbs run $300-$700 per side; a full set of used Euro/aftermarket replacement headlights runs $600-$1,500. Plastic-lens polishing only addresses the outer cover; internal reflector damage cannot be polished away.

Typical repair cost:$300 - $1,500

Research This Issue

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

On the 1997-2003 Audi A8, the 4.2 V8 in the D2 A8 (both the early 32-valve ABZ and the later 40-valve AKB/AUX/AYS/BFM) runs a vacuum-operated secondary air injection system with one combi valve per cylinder head, fed by small-diameter hard plastic vacuum lines that become brittle with heat and crack. Both banks have their own combi valve, and it is usually the hard vacuum line that goes to them that breaks and causes a vacuum leak and inoperable SAI. Owners report replacing vacuum hoses and the SAI relay only to have the CEL return, and then having to look at replacing the SAI pump (SAIP), the solenoid on top of the engine, and replacing/cleaning out the combi valves aft of each cylinder head, which involves carbon buildup in the cylinder head ports. Symptom is a check-engine light shortly after a cold start with P0410 (or banked variants P0491/P0492).

This issue also affects: Audi Q7, Audi S4, Volkswagen Jetta

Common Symptoms

  • Check engine light after cold start
  • Audible hissing from engine bay at cold start
  • Rough idle for first 30-90 seconds after cold start
  • Failed emissions/smog test
  • Pump noise (whining) on cold start

How to Fix

Diagnose by starting the engine cold so the SAI system runs and listening for the vacuum leak, then looking around for the crack. Sticky/partly opening combi-valve or slow running pump are all candidates — you can spin the pumps up using VCDS output tests to verify pump current draw. Replace brittle vacuum hose with silicone, test combi valves with a hand vacuum pump (they should hold vacuum and audibly click open), and if codes persist with new vacuum/valves the SAI ports in the head will need to be carbon-cleaned. The pump itself (smog pump) typically fails when a leaking combi valve allows exhaust moisture to back-feed and corrode the impeller.

Typical repair cost:$80 - $1,400

Research This Issue

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

On the 1994-2002 Audi A8, the VDO-built instrument cluster in the D2 A8 develops the same fading-pixel problem common across the VAG/VDO family: rows or columns of the central LCD (odometer, on-board computer, gear indicator, time) go dark or missing. <cite index="2-1">Replacement LCD screens are useful to repair Audi A4 B5 (VDO models from 1994 to 2000) and A8 D2 (VDO models from 1994 to 2002) instrument panels / speedometers.</cite> Faded out display, burned out horizontal and vertical lines, lack of contrast. In addition to pixel loss, the entire cluster can intermittently blank out, taking gauges and warning chimes with it. The instrument cluster failed as follows while driving: the central display lit up evenly and entirely, with no characters or symbols and then went blank; the tachometer, speedometer, temperature and fuel gauges dropped to zero at the same time; and the digital displays of time and mileage went blank.

Common Symptoms

  • missing pixels on central LCD
  • fading lines on display
  • blank odometer
  • blank gear indicator
  • intermittent total cluster blackout
  • distorted warning chime

How to Fix

Two fixes: (1) reseat/repair the ribbon cable bonded to the LCD — <cite index="1-19,1-20">VDO assembled the LCD display and silver ribbon cable with a heat bonding procedure, which makes the contacts loose connection very quickly, often within just a few years.</cite> (2) Send the cluster to a specialist (e.g., instrumentcluster.eu, German Auto Tech, pixelfix.net) for a replacement LCD soldered in. DIY ribbon-cable repair kits run $30–$80; <cite index="7-12">professional cluster repair runs approximately $300</cite>; full cluster replacement (with mileage re-coding) is $800+. <cite index="5-4">Replacing an instrument cluster can be a pain because in some cases it requires programming back to the vehicle if coded to the immobiliser, so it can work out to be quite costly.</cite> For total cluster blanking, pulling the cluster, unplugging for 30+ seconds, and reseating connectors sometimes resets it.

Typical repair cost:$30 - $800

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
High ConfidenceLast reported by owners May 2026Reviewed May 2026
NHTSA Recalls5 recalls

AIR BAGS:FRONTAL:DRIVER SIDE:INFLATOR MODULE

Volkswagen Group of America, Inc. (VW) is recalling certain 2000-2001 TT Roadster, 2000 TT Coupe, 1999 Audi A8, 1998-2000 Audi A6, and 1999-2000 Audi A4 vehicles equipped with Non-Azide Driver air bag Inflators (NADI) that do not contain phase stabilized ammonium nitrate (PSAN) propellant. Due to a manufacturing issue, the NADI inflators may absorb moisture, possibly causing the air bag to deploy improperly in the event of a crash.

Campaign #20V05600031/01/2020

POWER TRAIN:AUTOMATIC TRANSMISSION

VOLKSWAGEN IS RECALLING 13,900 MY 1996-2003 AUDI A8 VEHICLES EQUIPPED WITH A 5-SPEED AUTOMATIC TRANSMISSION. THE LOCKING CABLE MAY MOVE OUT OF POSITION OVER TIME. WITH THE LOCKING CABLE OUT OF POSITION, THE SHIFTER CAN BE MOVED OUT OF THE "PARK" POSITION EVEN IF THE IGNITION KEY IS NOT IN THE IGNITION LOCK.

Campaign #08V39700014/08/2008

STEERING:LINKAGES:ROD:RELAY:CONNECTING

VEHICLE DESCRIPTION: PASSENGER VEHICLES. THE TIE RODS OF THE STEERING ASSEMBLY ARE PROTECTED ON EACH SIDE BY A SEAL TO PREVENT MOISTURE AND DUST PARTICLES FROM ENTERING THE SWIVEL BEARING MECHANISM. IT IS POSSIBLE THAT SOME TIE ROD SEALS MAY NOT SEAL PROPERLY.

🔧
A mechanic who knows YOUR exact car
Answers tuned to your year, make, model & trim — not generic advice. Save your garage so it always has the right context.
Get ahead of Audi A8 problems — free
Leave your email and we'll alert you the moment there's a new recall or known issue for your Audi A8. Free, no account needed.

Don't see your problem? Describe your symptoms to get a diagnosis, or get a full repair guide.

Other Audi Models

Audi R830Audi Q329Audi A427Audi A623Audi S722Audi S419

Frequently Asked Questions

What are the most common Audi A8 problems?

According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 1999 Audi A8 has 7 documented issues. The most frequently reported are: D2 A8 4.2 V8 Timing Belt — Interval Retroactively Cut from 105k to 75k Miles (Interference Engine), 1998-1999 A8 Takata NADI Driver-Airbag Inflator Recall 69BT (20V056/22V471), Bosch 5.3 ABS Control Module Internal Failure (EBCM). Of these, 3 are rated critical and should be addressed promptly.

Is the Audi A8 reliable?

The 1999 Audi A8 has 7 known issues compiled from NHTSA recalls, manufacturer TSBs, and owner forum reports. 3 issues are rated critical: D2 A8 4.2 V8 Timing Belt — Interval Retroactively Cut from 105k to 75k Miles (Interference Engine) and 1998-1999 A8 Takata NADI Driver-Airbag Inflator Recall 69BT (20V056/22V471) and Bosch 5.3 ABS Control Module Internal Failure (EBCM). 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 A8 problems?

Repair costs for known Audi A8 issues range from $30 to $3,000, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, D2 A8 4.2 V8 Timing Belt — Interval Retroactively Cut from 105k to 75k Miles (Interference Engine), typically costs $1,500-$3,000 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 1997-2003 Audi A8 D2 A8 4.2 V8 Timing Belt — Interval Retroactively Cut from 105k to 75k Miles (Interference Engine)?

The D2 A8 4.2L V8 (both the early 32-valve ABZ and the later 40-valve AUX/AWN/AKB) is an interference engine driven by a rubber timing belt. The original published interval was 105K miles on the C5 and D2 4.2, until Audi retroactively changed it to 75,000 miles. Many original-own… Repairs typically run $1,500-$3,000. Severity: high.

What is the 1998-1999 Audi A8 1998-1999 A8 Takata NADI Driver-Airbag Inflator Recall 69BT (20V056/22V471)?

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.

Campaign #99V24800013/09/1999

STEERING:LINKAGES:ROD:RELAY:CONNECTING

VEHICLE DESCRIPTION: PASSENGER VEHICLES. THE TIE RODS OF THE STEERING ASSEMBLY ARE PROTECTED ON EACH SIDE BY A SEAL TO PREVENT MOISTURE AND DUST PARTICLES FROM ENTERING THE SWIVEL BEARING MECHANISM. IT IS POSSIBLE THAT SOME TIE ROD SEALS MAY NOT SEAL PROPERLY.

Campaign #00V41400006/12/2000

FUEL SYSTEM, GASOLINE:STORAGE:TANK ASSEMBLY:FILLER PIPE AND CAP

VEHICLE DESCRIPTION: PASSENGER VEHICLES EQUIPPED WITH A FUEL AND VAPOR LEAK DETECTION SYSTEM. A "BLIND COVER" AT THE FILLER NECK OF THE FUEL TANK MAY NOT SEAL PROPERLY ALLOWING FUEL VAPOR TO ESCAPE.

Campaign #01V25900015/08/2001

Enter your VIN at NHTSA.gov to check recalls specific to your vehicle.

Certain 1998-1999 Audi A8 vehicles may contain a Takata non-azide driver inflator that can absorb moisture and deploy improperly. NHTSA 20V056 originally listed the 1999 A8 branch, Audi 69BT campaign material lists 1998-1999 A8 vehicles, and NHTSA 22V471 corrects the filing to ad… Severity: high.

What is the 1997-2003 Audi A8 Bosch 5.3 ABS Control Module Internal Failure (EBCM)?

The Bosch 5.3 ABS/EBCM control module mounted to the side of the hydraulic pump unit suffers from internal solder joint and fine aluminum bond-wire fatigue, causing intermittent then permanent loss of ABS function. The Audi ABS pump & module system has been a very common failure… Repairs typically run $200-$600. Severity: high.

What is the 1997-2003 Audi A8 Pentosin CHF11S hydraulic system leaks (power steering pump, rack, hoses)?

The D2 A8's hydraulic system uses Pentosin mineral oil shared between the power steering pump, ZF rack with Servotronic module, and (on non-NA self-leveling cars) the rear shock accumulators. Owners report leaks in the middle of the pump where the two-piece housing is bolted toge… Repairs typically run $400-$2,500. Severity: medium.

What is the 1994-2002 Audi A8 Xenon headlight projector reflector blackening / lens clouding?

Factory-fitted options included halogen, D2S/H7 single-xenon, and D2R/H7 single-xenon headlights manufactured by Bosch (Automotive Lighting); the halogen H7 reflectors lose their reflective layer as it peels off from bulb heat and ageing, and the single-xenon 2.5-inch projectors… Repairs typically run $300-$1,500. Severity: medium.

What is the 1997-2003 Audi A8 Secondary Air Injection P0410/P0411 — Cracked Vacuum Lines, Stuck Combi Valves, Carbon-Clogged Head Ports?

The 4.2 V8 in the D2 A8 (both the early 32-valve ABZ and the later 40-valve AKB/AUX/AYS/BFM) runs a vacuum-operated secondary air injection system with one combi valve per cylinder head, fed by small-diameter hard plastic vacuum lines that become brittle with heat and crack. Both… Repairs typically run $80-$1,400. Severity: medium.

What is the 1994-2002 Audi A8 Instrument cluster LCD pixel fade / dead pixels on VDO display?

The VDO-built instrument cluster in the D2 A8 develops the same fading-pixel problem common across the VAG/VDO family: rows or columns of the central LCD (odometer, on-board computer, gear indicator, time) go dark or missing. <cite index="2-1">Replacement LCD screens are useful t… Repairs typically run $30-$800. Severity: low.