Audi A4 Common Faults in the UK

B9 (2015–2023) — D-segment executive saloon and Avant estate. One of the most popular used premium cars in the UK alongside the BMW 3 Series. Available as saloon and Avant estate. Key engines: 2.0 TFSI petrol (150–252 PS), 2.0 TDI diesel (136–190 PS), 35 TFSI mild hybrid (150 PS), 40 TFSI (190 PS), 40 TDI (204 PS). Updated 6 October 2026.

This guide covers the B9 (2015–2023) only. Older A4 generations have different engines and faults — for one of those, see how to check any car for known faults.

The Audi A4 B9 is a premium, refined executive car with strong build quality, but it requires disciplined Audi specialist maintenance to keep running costs manageable. The 2.0 TDI diesel is reliable on motorway mileage but has documented timing belt (not chain) service requirements — belt failure on the B9 2.0 TDI is an engine-write-off event. The 2.0 TFSI mild hybrid (post-2019) is the better choice for mixed UK driving. Avoid any B9 A4 without full documented service history — Audi's repair costs are high and an unmaintained A4 can quickly become very expensive.

Largest DVSA recall for the A4: R/2020/138, 34,982 vehicles in the whole recall — Moisture may enter the belt-driven starter-alternator. See the 3 DVSA recalls listed for this model.

MOT pass rate — official DVSA data

82.5% of Audi A4s registered 2015–2022 pass the MOT on the day (cars fixed during the test included), level with all cars registered in those years (83.1%). These are the cars this guide covers that were 3 to 12 years old when DVSA tested them in 2025, counted from 11,337 DVSA tests; a pass with rectification at the station counts as a pass here, and as a failure in DVSA's own initial-test measure.

Counting every registration year DVSA holds for the Audi A4 (2003–2022), which includes generations this guide does not cover, 77.3% pass on the day (cars fixed during the test included), from 24,990 tests.

Source: DVSA MOT Anonymised Data 2025 (Open Government Licence v3.0), a sample of the 2025 file (about one test in ten, from nine months). Class 4 tests in Great Britain, test type NT (a normal annual test), retests excluded. A pass, or a pass with rectification at the station, counts as a pass here (passed on the day); DVSA's own initial-test measure counts a rectified pass as a failure and so reports a lower figure. Testing in Northern Ireland is run separately by the DVA under its own rules. Compared against cars of the same registration years, because pass rates otherwise mostly measure how old a model's surviving fleet is.

See it by registration year and by mileage ↓

Asking prices — on Autoza

£6,495–£18,995, median £11,495

Cars advertised on 29 October 2026

Road Tax (UK) — VED, from the second year

£200/yr standard rate

£200/year standard rate from the second year, hybrids included — the alternative-fuel discount ended on 1 April 2025. A car registered from April 2017 with a list price over £40,000 when new adds the £440/year Expensive Car Supplement in years 2–6 (£640 in all). Cars registered 2001–2017 pay a CO2 band, roughly £20–£790/year (2026/27 rates).

Real-World Fuel Economy — owner-reported

49–57 mpg (2.0 TDI real-world UK motorway mixed); 38–47 mpg (35 TFSI MHEV real-world)

Insurance

Group 22–32. An Audi specialist rather than a main dealer usually costs less to service with.

The asking-price figures above are the middle 80% and the median of what sellers were asking on Autoza on 29 October 2026 — not what buyers pay — for Audi A4 cars registered 2015–2023. They are worked out from the cars on sale when this page is generated, and none is shown when fewer than 10 cars qualify. The road tax line comes from GOV.UK's vehicle tax rate tables (2026/27 rates). The other quick-stats values are indicative editorial estimates aggregated from owner-forum sentiment, recall data and reliability surveys. We do not publish a UK price index, and no figure here should be quoted as one.

Best and worst years to buy

We name a year as a best or worst buy only where the DVSA MOT table further down does not rate it the other way.

Best Years

2020, 2021

2019+ B9 facelift: mild hybrid (MHEV) system added to TFSI petrols, improved MMI infotainment with virtual cockpit standard, and most launch reliability issues resolved. The 35 TFSI MHEV is the most balanced engine choice — low tax, adequate performance, and no timing belt concern (uses a timing chain). The DVSA MOT table on this page rates 2019 registrations below all cars registered that year, so it is not named as a best-buy year.

Worst Years

2015

2015–2016 B9 launch cars: more reported MMI infotainment issues, some ZF gearbox calibration complaints on early DSG/S-Tronic automatics, and earlier fuel system issues on the 2.0 TDI before production revisions. The DVSA MOT table on this page rates 2016 registrations above all cars registered that year, so it is not named as a year to avoid.

Known faults — Audi A4 B9 (2015–2023)

How to read this list. This model’s DVSA safety recalls are listed in their own section below, largest first, each with DVSA’s reference and vehicle count. Everything else in this list is owner-reported: patterns that come up repeatedly with workshops, owner forums and reliability surveys. Those are worth checking on a viewing, but we hold no count of how many cars have each one, other than any survey share a card itself quotes. Treat an owner-reported item as a question to ask, not a fault this car has.

2.0 TDI timing belt service (interference engine)

Owner-reported · frequency unknownCritical — safety or catastrophic failure risk

Symptoms: No audible warning — belt failure is sudden and catastrophic. Prevention through scheduled service is the only protection.
Years affected: All B9 A4 2.0 TDI (2015–2023) — Audi recommended interval: every 80,000 miles or 4 years (whichever first). Many specialists recommend 55,000 miles or 4 years in UK stop-start conditions.
Indicative repair (UK): £700–£1,200 timing belt kit (preventive); £8,000–£15,000+ engine replacement if belt fails (the 2.0 TDI is an interference engine — belt failure destroys the engine)
What to check before buying: Ask for documented timing belt replacement history. If the car is at 55,000+ miles with no record of a belt change, factor the service into the purchase price or walk away. The 2.0 TDI's timing belt is one of the most important pre-purchase checks on any B9 A4. The 2.0 TFSI petrol uses a timing chain, but the pre-facelift 1.4 TFSI has a toothed belt too, so ask for its belt history as well.

MMI infotainment and virtual cockpit freezing

Owner-reported · frequency unknownMinor — wear-and-tear

Symptoms: MMI screen freeze; navigation crash; virtual cockpit going blank; MMI reboot loops
Years affected: 2015–2019 (older MMI generations) — Not mileage-related — software degradation over time
Indicative repair (UK): £0 — software update at Audi dealer; hardware replacement £600–£1,200 if MMI control unit fails
What to check before buying: Test all MMI functions during the test drive — navigation, Bluetooth, media, climate control (which is MMI-integrated on many trims). Ask if the latest Audi software update has been applied. Most MMI issues are software-related and resolved by an update.

S-Tronic DSG dual-clutch judder

Owner-reported · frequency unknownMajor — significant repair cost

Symptoms: Shudder or hesitation when pulling away from standstill; jerky low-speed changes; clutch grab in first gear
Years affected: 2015–2021 (7-speed S-Tronic DL382/DQ381 automatic) — Above 35,000 miles in urban use; can appear earlier if the scheduled gearbox oil service has been skipped
Indicative repair (UK): £400–£700 gearbox oil-and-filter service + software calibration; £1,500–£3,500 mechatronic or clutch pack replacement
What to check before buying: Test the S-Tronic at walking pace in traffic and pulling away on a slope. Any shudder is the known Audi/VAG DSG judder. These are wet-clutch boxes with a scheduled oil-and-filter service (the VW Group schedule for the same family is every 40,000 miles; check Audi’s schedule for the car), so ask for that service history. An unmaintained S-Tronic above 60,000 miles is a significant risk.

High-pressure fuel pump failure (2.0 TFSI EA888)

Owner-reported · frequency unknownMajor — significant repair cost

Symptoms: Hard starting; rough idle; fuel pressure warning; misfires
Years affected: 2015–2019 (EA888 Gen 3 TFSI) — Above 60,000 miles
Indicative repair (UK): £600–£1,200 high-pressure fuel pump; £200–£400 low-pressure fuel pump
What to check before buying: Test cold start behaviour. Any hesitation or extended cranking before starting suggests fuel system issues. Ask about any fuel pressure warning codes in the service history.

Suspension bushes and ball joint wear

Owner-reported · frequency unknownModerate — service-level fix

Symptoms: Clunking over speed bumps; vague steering; uneven tyre wear
Years affected: All years above 60,000 miles — 60,000+ miles on UK roads
Indicative repair (UK): £500–£1,200 front lower arm, subframe bush replacement
What to check before buying: Drive slowly over a speed bump at walking pace with the windows down. Any clunk from the front indicates suspension bush wear — common on B9 A4s above 60,000 miles. A ramp inspection takes 5 minutes to diagnose.

DVSA safety recalls for the Audi A4, largest first

These are the recalls DVSA lists for this model and its build years: every one of 10,000 or more vehicles, largest first, with DVSA’s own reference and figures. A recall covers only cars built in its dates and within its VIN range — check a particular car by registration through GOV.UK’s vehicle recall check. “Critical” here means DVSA’s own notice tells owners not to drive the car until it is fixed. It is never a size: “Large” means DVSA lists 10,000 or more vehicles in the recall.

Safety recall · R/2020/138Large recall — 34,982 vehicles
Moisture may enter the belt-driven starter-alternator
34,982 vehicles in the whole recall (DVSA’s figure for every model it covers) · built between 1 June 2017 and 31 March 2020 · recall launched 30 June 2020
Safety recall · R/2020/265Large recall — 11,936 vehicles
Moisture may enter the belt driven starter-alternator
It is possible that moisture may enter the belt-driven starter-alternator.
11,936 vehicles in the whole recall (DVSA’s figure for every model it covers) · built between 10 August 2018 and 11 March 2020 · recall launched 2 October 2020
Safety recall · R/2021/236Large recall — 10,089 vehicles
Rear axle suspension links nuts do not meet specifications
One or more nuts which do not meet the specifications may have been fitted on the rear axle suspension links.
10,089 vehicles in the whole recall (DVSA’s figure for every model it covers) · built between 7 November 2019 and 18 February 2021 · recall launched 25 June 2021

Source: DVSA vehicle recalls file (every recall since 1992), published under the Open Government Licence. Where DVSA gives one figure for a recall that covers several models, it is shown as the whole recall’s total.

Audi A4 MOT results by year and mileage

Measured from DVSA’s own MOT test records for tests carried out in 2025, not from owner reports.

By registration year

Against all cars registered in the same year, the MOT pass rate for the A4 was higher in 3, lower in 2 and level in 5 of the 10 registration years from 2013 to 2022 with enough tests to measure. The widest gap below is 2018 registrations: 81.6% against 84.5% for all cars registered that year. The widest gap above is 2014 registrations: 79.2% against 74.3%.

Pass rate here: passed on the day, cars fixed during the test included. Rows: every Audi A4 DVSA tested in 2025, by registration year (2013–2022), all engines and fuels together. 2013–2014 registrations are older generations of the A4 than this guide covers, shown for comparison; the guide’s own cars start in 2015. A registration year cannot separate two generations exactly when one replaced the other part-way through a year.

Audi A4 MOT pass rate (passed on the day, cars fixed during the test included) by registration year, against all cars registered the same year
Registered	A4	All cars that year	Difference
2022631 tests	90.3%	91.2%	−0.9 level
2021732 tests	90.0%	90.1%	−0.1 level
2020850 tests	88.0%	88.7%	−0.7 level
20191,338 tests	84.7%	86.9%	−2.2 lower
20181,451 tests	81.6%	84.5%	−2.9 lower
20172,319 tests	81.2%	82.2%	−1.0 level
20162,263 tests	82.1%	79.4%	+2.7 higher
20151,753 tests	75.5%	76.7%	−1.2 level
20141,735 tests	79.2%	74.3%	+4.9 higher
20131,600 tests	76.7%	71.9%	+4.8 higher

By mileage at the test

Against cars of the same age on the same mileage, the pass rate for the A4 was higher in every one of the 7 mileage bands with enough tests. How other models compare at the same mileage.

Show the table by mileage (7 bands)

Audi A4 MOT pass rate by odometer reading at the test, against cars of the same age on the same mileage
Mileage	A4	Same age and mileage	Difference
40k–60k3,133 tests	85.0%	83.5%	+1.5 higher
60k–80k3,900 tests	81.5%	77.5%	+4.0 higher
80k–100k4,086 tests	77.1%	72.3%	+4.8 higher
100k–120k3,319 tests	74.6%	68.4%	+6.2 higher
120k–140k2,910 tests	72.4%	66.4%	+6.1 higher
140k–160k2,158 tests	71.5%	65.4%	+6.1 higher
160k+3,365 tests	69.0%	65.1%	+4.0 higher

Only a major or dangerous defect fails an MOT. A minor defect is recorded on the certificate and the car still passes, and an advisory is not a failure at all.

We don’t give a recall count for the Audi A4: whether a recall applies depends on the individual car. Check the one you are looking at by entering its registration on GOV.UK’s vehicle recall checker, and see how to check a car for known faults for the other free checks.

Source: DVSA MOT Anonymised Data 2025 (Open Government Licence v3.0), a sample of the 2025 file (about one test in ten, from nine months) (3,459,000 tests). Class 4 tests in Great Britain, test type NT (a normal annual test), retests excluded. A pass, or a pass with rectification at the station, counts as a pass here (passed on the day); DVSA's own initial-test measure counts a rectified pass as a failure and so reports a lower figure. Odometer readings below 100 or above 400,000 miles are discarded as misreadings, and cars under three years old are excluded because no MOT is yet due. Sampled from nine months of 2025 (January, February, April, May, July, August, September, October and November). Testing in Northern Ireland is run separately by the DVA under its own rules. Registration years shown are cars 3 to 12 years old when tested; the smallest rests on 631 tests. A gap is called level when it is under one percentage point or inside the 95% sampling margin for that number of tests. Contains public sector information licensed under the Open Government Licence v3.0.

Who this car suits — and who should look elsewhere

Recommended for

Executive-segment buyers who want a refined, well-built premium saloon or estate. Motorway commuters (A4 Avant TDI is excellent value for high-mileage motorway use). Buyers who will use an Audi specialist for servicing.

Not recommended for

Buyers who cannot verify the 2.0 TDI timing belt service history. S-Tronic automatic buyers without gearbox oil-service history above 40,000 miles. Buyers wanting the lowest total cost of ownership — a Skoda Superb or Skoda Octavia diesel estate offers broadly similar space and refinement for significantly lower running costs.

Alternatives to consider

If the Audi A4 doesn't suit, these comparable models are worth a look in the UK market:

Audi A4: questions buyers ask

What are the most common faults on a used Audi A4 in the UK?

What is the best year to buy a used Audi A4 in the UK?

Best-buy years: 2020, 2021. 2019+ B9 facelift: mild hybrid (MHEV) system added to TFSI petrols, improved MMI infotainment with virtual cockpit standard, and most launch reliability issues resolved. The 35 TFSI MHEV is the most balanced engine choice — low tax, adequate performance, and no timing belt concern (uses a timing chain). The DVSA MOT table on this page rates 2019 registrations below all cars registered that year, so it is not named as a best-buy year.

What years of Audi A4 should I avoid in the UK?

Worst years: 2015. 2015–2016 B9 launch cars: more reported MMI infotainment issues, some ZF gearbox calibration complaints on early DSG/S-Tronic automatics, and earlier fuel system issues on the 2.0 TDI before production revisions. The DVSA MOT table on this page rates 2016 registrations above all cars registered that year, so it is not named as a year to avoid.

How much does a used Audi A4 cost in the UK in 2026?

What sellers were asking on Autoza on 29 October 2026, for Audi A4 cars registered 2015–2023: £6,495–£18,995, median £11,495 — the range is the middle 80% of asking prices. Those are asking prices, not what buyers paid, and not a UK price index. Prices vary by mileage, region and trim, so compare several adverts of the same year and mileage band before negotiating.

What is the road tax (VED) on a Audi A4 in the UK?

Annual road tax (VED): £200/year standard rate from the second year, hybrids included — the alternative-fuel discount ended on 1 April 2025. A car registered from April 2017 with a list price over £40,000 when new adds the £440/year Expensive Car Supplement in years 2–6 (£640 in all). Cars registered 2001–2017 pay a CO2 band, roughly £20–£790/year (2026/27 rates).

What real-world fuel economy does a Audi A4 achieve on UK roads?

Typical real-world consumption: 49–57 mpg (2.0 TDI real-world UK motorway mixed); 38–47 mpg (35 TFSI MHEV real-world).

How does a Audi A4 compare to its rivals?

Strong alternatives in the UK: BMW 3 Series, Mercedes C-Class, Skoda Superb, VW Passat, Volvo V60. Choose based on dealer network in your area, parts availability, and your priorities (running cost vs. cabin quality vs. badge).

Who is the Audi A4 most suitable for?

Who should NOT buy a Audi A4?

Are there safety recalls on the Audi A4?

DVSA lists 3 safety recalls for the Audi A4 that this guide shows or names, the largest first: R/2020/138 (34,982 vehicles in the whole recall, built between 1 June 2017 and 31 March 2020): Moisture may enter the belt-driven starter-alternator; R/2020/265 (11,936 vehicles in the whole recall, built between 10 August 2018 and 11 March 2020): Moisture may enter the belt driven starter-alternator; R/2021/236 (10,089 vehicles in the whole recall, built between 7 November 2019 and 18 February 2021): Rear axle suspension links nuts do not meet specifications. Whether a particular car is affected depends on its build date and VIN, so check its registration on GOV.UK (gov.uk/check-vehicle-recall) before you buy.

Is the 2.0 TDI timing belt service (interference engine) on the Audi A4 a serious problem?

Owner-reported, frequency unknown: 2.0 TDI timing belt service (interference engine) comes up in owner forums and workshop reports for the Audi A4, but how often it happens is not known, so treat it as a question to ask rather than a fault every car has. Symptoms: No audible warning — belt failure is sudden and catastrophic. Prevention through scheduled service is the only protection. Years affected: All B9 A4 2.0 TDI (2015–2023). Audi recommended interval: every 80,000 miles or 4 years (whichever first). Many specialists recommend 55,000 miles or 4 years in UK stop-start conditions. Indicative repair cost in the UK: £700–£1,200 timing belt kit (preventive); £8,000–£15,000+ engine replacement if belt fails (the 2.0 TDI is an interference engine — belt failure destroys the engine). What to check before buying: Ask for documented timing belt replacement history. If the car is at 55,000+ miles with no record of a belt change, factor the service into the purchase price or walk away. The 2.0 TDI's timing belt is one of the most important pre-purchase checks on any B9 A4. The 2.0 TFSI petrol uses a timing chain, but the pre-facelift 1.4 TFSI has a toothed belt too, so ask for its belt history as well.

Is the S-Tronic DSG dual-clutch judder on the Audi A4 a serious problem?

Owner-reported, frequency unknown: S-Tronic DSG dual-clutch judder comes up in owner forums and workshop reports for the Audi A4, but how often it happens is not known, so treat it as a question to ask rather than a fault every car has. Symptoms: Shudder or hesitation when pulling away from standstill; jerky low-speed changes; clutch grab in first gear. Years affected: 2015–2021 (7-speed S-Tronic DL382/DQ381 automatic). Above 35,000 miles in urban use; can appear earlier if the scheduled gearbox oil service has been skipped. Indicative repair cost in the UK: £400–£700 gearbox oil-and-filter service + software calibration; £1,500–£3,500 mechatronic or clutch pack replacement. What to check before buying: Test the S-Tronic at walking pace in traffic and pulling away on a slope. Any shudder is the known Audi/VAG DSG judder. These are wet-clutch boxes with a scheduled oil-and-filter service (the VW Group schedule for the same family is every 40,000 miles; check Audi’s schedule for the car), so ask for that service history. An unmaintained S-Tronic above 60,000 miles is a significant risk.

Is the High-pressure fuel pump failure (2.0 TFSI EA888) on the Audi A4 a serious problem?

Owner-reported, frequency unknown: High-pressure fuel pump failure (2.0 TFSI EA888) comes up in owner forums and workshop reports for the Audi A4, but how often it happens is not known, so treat it as a question to ask rather than a fault every car has. Symptoms: Hard starting; rough idle; fuel pressure warning; misfires. Years affected: 2015–2019 (EA888 Gen 3 TFSI). Above 60,000 miles. Indicative repair cost in the UK: £600–£1,200 high-pressure fuel pump; £200–£400 low-pressure fuel pump. What to check before buying: Test cold start behaviour. Any hesitation or extended cranking before starting suggests fuel system issues. Ask about any fuel pressure warning codes in the service history.

Check these next

The guide above is about the Audi A4 as a model. These are about the car in front of you.

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