Audi · Known Issues

2012 Audi S8 Problems: 2 Issues Every Owner Should Know

2012 model year · NHTSA recalls, manufacturer TSBs, and owner forum reports · Updated June 2026

According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2012 Audi S8 has 2 documented known issues, with 1 rated critical. The most serious is 5.2 V10 Timing Chain Tensioner / Guide Wear (D3 Cold-Start Rattle) ($2,500-$6,000 repair). Across all issues, repair costs range from $150 to $6,000. DIY maintenance guides at au7o.io.

All 2 Known Issues

On the 2007-2012 Audi S8 5.2L FSI V10 (BSM), the D3-generation S8 uses the 5.2L FSI V10 (shared lineage with the Lamborghini Gallardo/R8 V10). Its timing is driven by chains with plastic guides and hydraulic tensioners located at the rear of the engine. Over time and with deferred oil changes, the tensioners and guides wear, producing a rattle on cold startup that can persist. If a guide breaks or the chain skips, valve-to-piston contact can cause catastrophic engine damage. Access is poor (rear of the V10), making this an engine-out-level job and one of the most expensive risks on the D3 S8.

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

Common Symptoms

Rattle from engine on cold startup
Metallic chain noise from rear of engine
Rough running or misfire if timing has shifted
Check engine light for camshaft/crankshaft correlation

How to Fix

Investigate any cold-start rattle promptly: inspect tensioner travel and guide condition. Replace the timing chains, tensioners, and plastic guides as a set with updated genuine parts; this is a major, labor-intensive repair (often engine-out). Strictly follow short oil-change intervals with the correct grade to maximize tensioner/guide life, and address any low-oil-pressure condition immediately. Do not drive a V10 with a persistent timing rattle.

What you need to fix it

The exact parts — OEM, plus what owners actually use. Skip the internet hunt.

Timing chains, full V10 set (4 chains) — outer/cam chains + center drive chains
OEM06E109465AMOwners use06E109465AN, 06E109465AP, 06E109465AQ$100–$140
The 5.2 V10 BSM (D3 S8, 2007-2012) uses FOUR timing chains, not one — they MUST be replaced as a set: 06E109465AM (center upper), 06E109465AN (left bank), 06E109465AP (right bank), 06E109465AQ (lower/center, the V10-extra chain). Verified on genuine Audi catalogs (parts.audiusa.com / Audi Gilbert) a
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Upper timing chain tensioner — left bank (cylinder head)
OEM079109217ROwners use079109217AA, INA/Febi 079109217, Iwis equivalent$90–$130
Upper (cylinder-head) chain tensioner, left bank. Genuine Audi PN 079109217R fits 4.2 V8 / 5.2 V10 FSI engines (BAR/BSM/BVJ/BXA/CAUA), 2006-2012 S5/A6/A8/S6/S8/Q7/Touareg — confirmed in the ARZ-Tuning BSM kit and ECS/Europa listings. ~$94 genuine. Supersession 079109217AA. Replace both upper tension
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Upper timing chain tensioner — right bank (cylinder head)
OEM079109218ROwners use079109218AA, INA/Febi 079109218, Iwis equivalent$110–$140
Upper (cylinder-head) chain tensioner, right bank — the mirror of 079109217R. Genuine Audi PN 079109218R, fits 4.2 V8 / 5.2 V10 FSI (BSM) 2006-2012; ~$124 genuine (ECS). Listed in the ARZ-Tuning 14-pc BSM kit. Supersession 079109218AA.
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Lower / main timing chain tensioner — upper position (079109507M / AM)
OEM079109507AMOwners use079109507M, INA 079109507AM, Febi equivalent$150–$240
Main drive-chain hydraulic tensioner (the 'upper' of the 507-series pair on the V10). Genuine PN 079109507AM (earlier 079109507M). Confirmed on Europa Parts as upper tensioner fitting D3 S8 5.2 V10 BSM 2007-2009 and on the ARZ-Tuning BSM kit. These hydraulic tensioners are a primary wear item in the
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Lower / main timing chain tensioner — lower position (079109507AF)
OEM079109507AFOwners useINA 079109507AF, VAG 079109507AF, Febi equivalent$160–$240
Second main hydraulic chain tensioner (the 'lower' of the 507-series pair). Genuine PN 079109507AF confirmed on parts.audiusa.com as 'Audi S8 Engine Timing Chain Tensioner' and on Europa Parts as lower tensioner fitting D3 S8 5.2 V10 BSM 2007-2009 (also used on later R8/Huracan V10). ~$164-240. Repl
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Timing chain guide rail — center / camshaft-to-camshaft (079109469AL)
OEM079109469ALOwners use079109469AC, 079109469AD, Febi/Iwis 079109469$40–$90
Plastic chain guide rail (center, cam-to-cam). Genuine PN 079109469AL listed in the ARZ-Tuning BSM kit and sold for V8/V10 FSI (BAR/BSM/etc). The brittle plastic guides are the part that breaks and lets the chain skip — exactly the catastrophic-failure path in the issue. Several suffix variants exis
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Timing chain guide rail — lower / second guide (079109469AM)
OEM079109469AMOwners use079109470, 079109469AC, Febi/Iwis 079109469$38–$70
Second plastic guide rail. Genuine PN 079109469AM (~$38 sale) listed alongside 079109469AL in the ARZ-Tuning BSM kit. Related genuine guide PN 079109470 (Pelican/EuroSport) also fits the 4.2/5.2 FSI guide assembly. Replace all guide rails as a set — leaving an old brittle guide in place defeats the
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Chain tensioner seals / gaskets (4) — for the 507-series tensioners
OEM079109139JOwners use079109139K, 079109139L, 079109139A$5–$20
Sealing rings/gaskets for the hydraulic chain tensioners — the four 079109139-series seals (J/K/L/A or M) bundled in the genuine V10 BSM timing-chain kit (per the ARZ-Tuning 14-pc kit). Must be renewed whenever the tensioners come out. Low cost per seal; sold individually or in the kit.
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Engine oil — VW 502 00 spec 5W-40 (~10 L / 10.6 qt) for refill after the job
Owners useCastrol EDGE 5W-40 502 00, Liqui Moly 5W-40 502 00, Ravenol VST 5W-40 502 00$70–$120
Not a single PN (consumable). The BSM V10 holds 10 L / 10.6 US qt and REQUIRES a VW 502 00 approved 5W-40 full-synthetic; strict short oil-change intervals with this grade are the documented mitigation that maximizes tensioner/guide life. Plan a fresh fill (plus a new oil filter, separate PN) after
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Typical repair cost:$2,500 - $6,000

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Community Reported

Medium ConfidenceVerified0 reportsLast reported by owners Invalid DateReviewed Jun 2026

On the 2007-2018 Audi S8, the S8's energy-management strategy depends on a battery monitoring sensor and the battery/energy control module that govern charging, load shedding, and (on later cars) start-stop. When the module mis-reads battery state, or the battery is replaced without proper coding/adaptation, owners get warnings ('start-stop unavailable', electrical-system fault), erratic charging, and accelerated battery wear. Separately, control modules (notably the gateway and infotainment/convenience modules) can stay awake and cause parasitic drain that flattens the battery overnight. Installing a battery requires coding the new battery's specs to the energy-management module via the gateway long-adaptation; skipping this is a frequent cause of repeat complaints.

Common Symptoms

Dead or weak battery overnight (parasitic drain)
'Start-stop not available' or electrical-system warning
Erratic charging / battery warning light
Repeated premature battery failure
Modules staying awake after lock

How to Fix

Diagnose parasitic draw with a current clamp and pull-fuse method to find the module that fails to sleep (commonly gateway/convenience/MMI). When replacing the battery, fit the correct AGM/EFB type and code it (capacity + part/serial) using the [Long Adaptation] under the 19-CAN Gateway via VCDS/ODIS so the energy manager regulates charging correctly. Inspect/replace the battery monitoring sensor on the negative terminal if state-of-charge readings are wrong. Address any module that won't enter sleep with a software update or replacement.

What you need to fix it

The exact parts — OEM, plus what owners actually use. Skip the internet hunt.

Battery — AGM, 105Ah/950A (D4 S8, 2013-2018)
OEM000915105CFOwners useVarta A4 / H15 (605901095), Bosch S5 A11, BCI Group 49 / DIN H15$280–$420
Core part of the fix. Factory AGM for the D4 A8/S8 (4.0T V8). 12V 105Ah, 580A DIN / 950A EN. When fitting it the energy manager MUST be coded (capacity 105Ah + new part/serial) via Long Adaptation under the 19-CAN Gateway with VCDS/ODIS, or charging/start-stop misbehaves. Group 49 / H15 case. CF AGM
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Battery — 110Ah/850A (D3 S8, 2007-2009)
OEM000915105DLOwners useVarta H9 / N9 (605901096), Bosch S6 / S5 A13, BCI Group 49 / DIN H9$250–$400
Era-correct battery for the D3 S8 (5.2 V10). OEM DL is a 12V 110Ah, 520A DIN / 850A EN lead-calcium (flooded) unit, group 49/H9. Many owners upgrade to the 105Ah AGM (000915105CF) which fits the same trunk tray; either way the energy-management module needs coding/adaptation after replacement. eBay/
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Battery monitoring / current sensor on negative terminal (D4, 2013-2018)
OEM4H0915181Owners use8X0915181 (interchange listed by aftermarket suppliers), Getfarway battery negative sensor cable (2008-2018 fitment)$60–$180
Battery Energy Management (BEM) current sensor integrated into the negative battery cable on the D4 A8/S8 — replace if state-of-charge readings are wrong. '4H' is the D4 A8/S8 chassis prefix. Genuine Audi catalogs the same family for adjacent platforms as 4K0915181A/E (later) and 8T0915181 (B8); 4H0
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Battery energy-management control unit / current sensor (D3, 2007-2009)
OEM4E0910181COwners usesupersedes 4E0910181 / 4E0910181A / 4E0910181B, 4E0915181 (earlier energy-management module designation)$90–$260
Era-correct battery current sensor / energy-management unit for the D3 A8/S8 — '4E' is the D3 chassis prefix. Confirmed on genuine Audi USA as the Battery Current Sensor for the 2007 S8. Mounts at the negative terminal and feeds state-of-charge to the alternator/energy manager; replace if SoC data i
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Data-bus diagnostic interface / Gateway control module J533 (D4, 2011-2018) — only if a module won't sleep
OEM4H0907468Owners userevision suffixes incl. 4H0907468AC, Lear gateway module (OEM supplier)$200–$500
Secondary/conditional part. Only needed if parasitic-drain diagnosis traces to the gateway (or a CAN module) that will not enter sleep and a software update doesn't fix it. J533 sits behind the glovebox on the D4 A8/S8; a replaced gateway must be coded. '4H' = D4 A8/S8. Used/refurb ~$200-300, new ge
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Part links may earn au7o a commission. Confirm fitment by VIN before buying.

Typical repair cost:$150 - $900

Research This Issue

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Community Reported

Medium ConfidenceVerified0 reportsLast reported by owners Invalid DateReviewed Jun 2026

Frequently Asked Questions

What are the most common Audi S8 problems?

According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2012-2012 Audi S8 has 2 documented issues. The most frequently reported are: 5.2 V10 Timing Chain Tensioner / Guide Wear (D3 Cold-Start Rattle), Battery Management / Energy Control Module Faults and Parasitic Drain. Of these, 1 is rated critical and should be addressed promptly.

Is the Audi S8 reliable?

The 2012-2012 Audi S8 has 2 known issues compiled from NHTSA recalls, manufacturer TSBs, and owner forum reports. 1 issue is rated critical: 5.2 V10 Timing Chain Tensioner / Guide Wear (D3 Cold-Start Rattle). 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 S8 problems?

Repair costs for known Audi S8 issues range from $150 to $6,000, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, 5.2 V10 Timing Chain Tensioner / Guide Wear (D3 Cold-Start Rattle), typically costs $2,500-$6,000 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2007-2012 Audi S8 5.2 V10 Timing Chain Tensioner / Guide Wear (D3 Cold-Start Rattle)?

The D3-generation S8 uses the 5.2L FSI V10 (shared lineage with the Lamborghini Gallardo/R8 V10). Its timing is driven by chains with plastic guides and hydraulic tensioners located at the rear of the engine. Over time and with deferred oil changes, the tensioners and guides wear… Repairs typically run $2,500-$6,000. Severity: high.

What is the 2007-2018 Audi S8 Battery Management / Energy Control Module Faults and Parasitic Drain?

The S8's energy-management strategy depends on a battery monitoring sensor and the battery/energy control module that govern charging, load shedding, and (on later cars) start-stop. When the module mis-reads battery state, or the battery is replaced without proper coding/adaptati… Repairs typically run $150-$900. Severity: medium.

2012 Audi S8 Problems: 2 Issues Every Owner Should Know

All 2 Known Issues

2007-2012 Audi S8: 5.2 V10 Timing Chain Tensioner / Guide Wear (D3 Cold-Start Rattle)#

Common Symptoms

How to Fix

What you need to fix it

Research This Issue

2007-2018 Audi S8: Battery Management / Energy Control Module Faults and Parasitic Drain#

Common Symptoms

How to Fix

What you need to fix it

Research This Issue

Other Audi Models

Frequently Asked Questions

What are the most common Audi S8 problems?

Is the Audi S8 reliable?

How much does it cost to fix common Audi S8 problems?

What is the 2007-2012 Audi S8 5.2 V10 Timing Chain Tensioner / Guide Wear (D3 Cold-Start Rattle)?

What is the 2007-2018 Audi S8 Battery Management / Energy Control Module Faults and Parasitic Drain?