Generations
8T — First Generation
2007–2016
4.2 V8 FSI, 3.0 TFSI Supercharged
Top issues to watch for
The most serious Audi S5 problems ranked by severity. We track 6 known issues — here are the ones you need to know about first.
Major
DSG mechatronic unit failure (8T)
The DSG mechatronic unit is the hydraulic control module that operates clutch engagement and gear selection in the dual-clutch transmission. The unit contains solenoid valves, pressure sensors, and a control module that frequently fail due to heat cycling and contaminated transmission fluid. NHTSA data shows 15 complaints specifically mentioning mechatronic failure causing loss of drive. This issue is shared with the S4 B8 and affects all DSG-equipped S5 models. Later software updates improved reliability but did not eliminate the underlying hardware vulnerability.
What happens if ignoredComplete mechatronic failure leaves the car unable to engage any gear, requiring recovery. The transmission may enter limp mode with only one gear available. A replacement mechatronic unit costs £2,500-£4,000 including programming. Some failures can be temporarily resolved with software updates, but hardware faults require unit replacement.
Independent garage
£2,000–£3,500
Specialist
£2,500–£4,000
Main dealer
£3,500–£5,500
Parts only
£1,800–£2,800
Major
Same as S4 B8
The 3.0 TFSI supercharged engine shares the S4 B8's documented cooling system vulnerabilities including thermostat housing failure, PCV valve carbon build-up, and water pump impeller degradation. The supercharger generates additional heat stress on cooling components compared to naturally aspirated engines. These issues cause overheating, oil consumption, and potential engine damage if not addressed. NHTSA data shows 4 overheating complaints and 4 water pump failures on US-spec S5 models with the same engine family.
What happens if ignoredThermostat failure causes overheating and potential head gasket damage. Water pump failure can cause complete coolant loss and engine seizure. PCV valve failure leads to excessive oil consumption and carbon build-up on intake valves. Combined repair costs range from £300-£800 for individual components, but multiple simultaneous failures are common.
Independent garage
£300–£600
Specialist
£400–£800
Main dealer
£600–£1,200
Parts only
£150–£400
Minor
Suspension bush wear (8T)
MOT data shows S5 models failing suspension bush inspections at 415.4x the fleet average, particularly affecting 4.2L V8 models at 40,000-60,000 miles. The heavier V8 engine and performance-oriented suspension setup accelerate wear on control arm bushes, anti-roll bar links, and subframe mounts. This affects ride quality and handling precision but is not immediately dangerous. The trend is worsening across the model range based on 2020-2024 data.
What happens if ignoredWorn suspension bushes cause poor ride quality, imprecise handling, and accelerated tyre wear. While not immediately dangerous, severely worn bushes can affect braking stability and cornering predictability. Individual bushes cost £20-£100 each but labour-intensive replacement means total costs accumulate quickly.
Independent garage
£200–£600
Specialist
£300–£800
Main dealer
£500–£1,200
Parts only
£100–£300
Minor
Engine management light - 4.2L V8 (8T)
These faults rarely affect driveability but cause MOT emission failures.
What happens if ignoredA illuminated MIL will cause an automatic MOT failure. Most faults are emissions-related and do not affect driveability, but diagnosis is required to identify the specific component failure. Lambda sensors cost £100-£200 each, secondary air pump repairs £300-£600. Ignoring the warning can lead to catalytic converter damage costing £800-£1,500.
Independent garage
£150–£400
Specialist
£200–£600
Main dealer
£300–£800
Parts only
£80–£300
2 more known issues tracked
Including wear items, electrical niggles, and generation-specific problems. Check a specific car to see which issues apply to its age and mileage.
Check a specific car →MOT failure hotspots
Based on DVSA MOT test data. These are the items where the Audi S5 fails at a significantly higher rate than the average car.
Exhaust system damage
Bodywork · 100-120k miles
MOT failure rate: 15x the fleet average
Sample: 568 tests
Free play in the steering, measured at the rim ...
Steering · 120-150k miles
MOT failure rate: 7.9x the fleet average
Sample: 357 tests
Tyre cords visible or damaged
Tyres · 40-60k miles
MOT failure rate: 7.1x the fleet average
Sample: 447 tests
ABS fault
Suspension · 100-120k miles
MOT failure rate: 6.8x the fleet average
Sample: 568 tests
Tyre seriously damaged
Tyres · 40-60k miles
MOT failure rate: 5.1x the fleet average
Sample: 447 tests
Buying a Audi S5?
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Related
Audi S5 reliability FAQs
What are the most common problems with the Audi S5?
The Audi S5 has 6 known issues across 3 severity levels. The most common problems relate to DSG mechatronic unit failure (8T) and Same as S4 B8.
Is the Audi S5 reliable?
The Audi S5 has 0 dangerous and 2 major known issues. No dangerous issues are tracked, which is a positive sign.
How much does it cost to fix Audi S5 problems?
Repair costs range widely. The most significant issue (DSG mechatronic unit failure (8T)) costs £2,000–£3,500 at an independent garage. Minor issues can be under £200. Always get a full inspection before buying.