Common Problems with the Audi A4
FixMyCar explores common problems with the Audi A4 and average repair costs.
Compare Audi A4 repair quotesEllie Dyer-Brown
Wednesday November 05 2025
8 min read
Introduced in 1994, the A4 is part of a line of compact executive cars produced by German automaker Audi.
This guide examines known issues with the A4, providing owners and potential buyers with insights into specific faults and their average repair costs.
In a nutshell: The A4’s reliability is mixed. Recurring issues include automatic gearbox/torque-converter faults on older cars, electrical problems and blower-motor failures, plus AdBlue/NOx system faults on some diesels. Later models may see infotainment glitches, and convertibles can suffer roof hydraulic/sensor failures.
What’s wrong with the Audi A4?
Audi A4 convertible problems
Convertible versions of the A4 are known to develop problems with the roof and its related parts, including hydraulic pump motor failure, hydraulic leaks, wiring issues and frame position sensor faults.
Average convertible roof repair price: £114.66
Audi A4 automatic transmission problems
Numerous A4 owners have reported automatic transmission problems, including solenoid failure, worn torque converter needle bearings and torque converter failure. Signs of a faulty automatic transmission typically include a burning smell, unusual sounds and rough gear changes.
The average price of an Audi A4 automatic transmission diagnostic is £124.50. For a repair, it’s £297.01.
Average automatic transmission diagnostic price: £169.55
Audi A4 electrical issues
A range of electrical issues can affect the A4, from failed window motors to display screen outages. The best thing to do if you encounter these problems is to book a diagnostic test.
Average electrical fault diagnosis price: £71.40
Audi A4 AdBlue fault
Some A4 owners have also reported faults with the AdBlue system, triggering a dashboard warning light. Possible causes include a blocked injector, broken sensor or faulty pump.
Average AdBlue repair price: £170.56
Recent recalls
| Recall number | Date | Reason |
|---|---|---|
| R/2022/036 | 14.02.22 | Following a previous campaign the toe and/or camber values on the rear axle may in certain circumstances incorrectly be changed without this being noticed. |
| R/2021/236 | 25.06.21 | One or more nuts which do not meet the specifications may have been fitted on the rear axle suspension links. |
| R/2020/302 | 26.10.20 | The seat frame may not have been bolted correctly to the seat rail on the driver and/or front passenger side. |
| R/2020/265 | 02.10.20 | It is possible that moisture may enter the belt-driven starter-alternator. |
| R/2020/138 | 30.06.20 | It is possible that moisture may enter the belt-driven starter-alternator. |
| R/2019/149 | 09.05.19 | An error in the casting process may affect the rigidity of the shock absorber fork. |
| R/2019/175 | 03.06.19 | Hinged towing bracket on which the locking mechanism in the hinge module could be faulty. |
| R/2018/365 | 14.12.18 | Air bag securing bolts may not be to the correct torque. |
| R/2018/152 | 11.06.18 | On affected vehicles moisture may enter the electronic components and cause overheating and failure of the additional coolant pump. Localised smoulder damage cannot be ruled out and in individual cases may cause vehicle to catch fire. |
| R/2018/086 | 30.04.18 | The aluminium trim may become detached from the loud speaker trim in the front or rear doors. Cuts and other injuries from the sharp edges may occur. |
Audi A4 2005-2008 problems
Drivers have encountered the following problems with the third-generation A4.
1. Central locking failure
Various issues have been reported with the A4’s central locking system, including doors locking out of sync or failing to lock at all. Often, this can be due to a faulty sensor or broken lock mechanism.
What repair is needed for central locking failure, and how much does it cost?
You’ll need to contact an auto locksmith to fix the problem. The average price of a central locking system repair for an A4 on FixMyCar is £73.50.
2. Noisy interior
Some of the A4’s interior trim, including the glovebox, can be noisy when the car is in motion, making rattling or squeaking noises.
What repair is needed for a noisy interior, and how much does it cost?
Unfortunately, these noises are a design flaw rather than a problem that can be fixed. They don’t affect all models, so if you’re in the market for a third-gen A4, it’s worth keeping an eye out for this on test drives.
3. Automatic transmission problems
The torque converter in automatic A4s is notorious for failing - an issue which is, unfortunately, expensive to fix. Signs of a failing torque converter include loss of acceleration, leaking transmission fluid and slipping between gears.
What repair is needed for automatic transmission problems, and how much does it cost?
The average price of an auto gearbox repair for an A4 on FixMyCar is £311.78.
Audi A4 2008-2015 problems
Drivers have encountered the following problems with the fourth-generation A4.
1. Squeaky brakes
A squeaking noise when you press the brake pedal usually indicates worn brake pads. However, with the A4, it can have a different cause: the brake calliper guide pins. Occasionally, these guide pins need re-lubricating to prevent the noise.
Here are five brake problems you shouldn't ignore.
What repair is needed for squeaky brakes, and how much does it cost?
The guide pins need lubricating, which is a relatively easy job. The average price of an A4 brake repair is £115.75.
2. Failed blower motor
The blower motor is a fan that pushes temperature-controlled air around your car based on the climate control settings. Blower motor failure is notoriously common in A4s, preventing drivers from using the heating system. This can also be dangerous since it means you don’t have a way to demist your windscreen.
What repair is needed for a failed blower motor, and how much does it cost?
Replacing the blower motor should cost between £100 and £300.
3. Centre driveshaft bearing failure
Audi A4s fitted with a quattro four-wheel drive system sometimes experience issues with the centre driveshaft bearing. Listen for a high-pitched whining noise from the vehicle’s underside as you drive at speeds between 30-40 mph - this is a sign you need to get the bearing checked out.
What repair is needed for a centre driveshaft bearing failure, and how much does it cost?
The driveshaft bearing needs replacing. This will typically cost between £200 and £500.
4. Leaky bulkhead seal
Some A4 owners have reported hearing a whistling sound when speeding up due to a leaking bulkhead seal.
What repair is needed for a leaky bulkhead seal, and how much does it cost?
Audi has issued a repair kit for this problem with the part number: AKL.450.005.05.
Audi A4 2015-present problems
Drivers have encountered the following common faults with the fifth-generation A4.
1. Faulty infotainment system
The infotainment system in some fifth-gen models can be faulty, with owners reporting flickering screens and connectivity issues.
What repair is needed for a faulty infotainment system, and how much does it cost?
The best thing to do if you’re experiencing infotainment issues is to take your car to an Audi specialist to check for software updates and potentially run a diagnostic test.
The average price of an Audi A4 diagnostic test booked through FixMyCar is £62.76.
2. Rattling interior
A4s generally have a high build quality, but some suffer from rattling and squeaking noises from the interior trim.
What repair is needed for a rattling interior, and how much does it cost?
Unfortunately, there isn’t much you can do to fix this problem because it isn’t a fault - it’s caused by the way the car is built. If you’re in the market for an A4, make sure you listen for any potentially annoying noises on test drives.
Years to avoid
Based on well-documented fault patterns, these are the Audi A4 years/variants to be more cautious about:
2009–2012 (B8, 2.0 TFSI petrol): Higher risk of excessive oil consumption from piston/ring wear. Many needed rebuilds or updated parts.
2005–2014 (B7/B8 with Multitronic CVT): Front-wheel-drive Multitronic gearboxes are prone to juddering and control-unit/clutch-pack failures, especially if fluid changes were skipped.
2016–2018 (early B9 diesels): More reports of AdBlue tank/heater and NOx-sensor faults, leading to warnings or limp mode if not rectified.
Tip: If you’re looking at one of these years, check for a full service record, documented major engine/gearbox work and evidence of any recall compliance (particularly for airbags, automatic transmission and AdBlue systems).
Is the Audi A4 reliable?
In What Car?’s latest Reliability Survey, the A4 came in 13th place out of 20 cars in the executive car category with a score of 86.6%, putting it above the Mercedes C-Class but below the BMW 3 Series. Audi, as a brand, came 26th out of 31 manufacturers with a score of 89%.
Overall, the A4's reliability record is mixed. Although it has a high build quality, it has also suffered from numerous expensive problems over the years.
Read our A4 owners' guide to learn more.
Most reliable model years
2013–2015 (late B8 facelift): By this point, the 2.0 TFSI oil-consumption issue was largely resolved and build quality is consistently strong. The 2.0 TDI models in these years are especially well-regarded for longevity when serviced on schedule. Avoid models with Multitronic gearboxes.
2019–present (later B9 builds): Post-2019 cars benefit from improved AdBlue hardware and updated NOx sensors, along with more refined electronics. The 7-speed S tronic in these later models is generally robust when serviced correctly.
In both cases, a full service history and evidence of any recall/software updates is the best indicator of long-term reliability.
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Ellie is FixMyCar's Content Manager. She has over three years of experience writing about cars and regularly collaborates with automotive experts to provide trustworthy advice for drivers that is easy understand. Her work has been featured in Yahoo! Finance, iNews, The Daily Express and The Sun. She has a BA in English literature and an MA in creative writing from Durham University. Outside of work, Ellie follows F1 and eagerly awaits Ferrari's next era of dominance in the sport. She drives a Suzuki Swift.