Common Problems with the Mercedes A Class
FixMyCar discusses common problems with the Mercedes A-Class and average repair costs.
Compare Mercedes A-Class repair quotesEllie Dyer-Brown
Monday January 26 2026
11 min read
Introduced in 1997, the Mercedes A-Class is a classy and comfortable compact car that's great to drive and packed with the latest tech.
This guide examines known issues with the A-Class, providing owners and potential buyers with insights into specific faults and their average repair costs.
In a nutshell: The Mercedes A-Class is a bit of a mixed bag for reliability. The most common issues include electrical faults, automatic gearbox problems and DPF blockages on diesels used for short trips. Newer W177 models are generally reliable (especially hybrids), while the 2013-2018 W176 is known for more problems, so condition and service history matter.
What's wrong with the Mercedes A-Class?
Drivers are searching online for information about the following problems.
Mercedes A-Class 1.5 diesel problems
The most common headaches with the 1.5 diesel tend to be emissions-related. If the car is mainly used for short, stop-start trips, the DPF warning light can come on because the filter isn’t getting the high-temperature runs it needs to regenerate properly, which can trigger limp mode until it’s sorted.
Mercedes A-Class automatic gearbox problems
A-Class automatics can develop jerky gear shift issues and may trigger a dashboard warning. Some reports describe faults that require replacement of the gearbox control unit. On newer cars, transmission faults can force the car into limp mode.
Mercedes A-Class 1.6 petrol engine problems
On A-Class models with the 1.6 petrol engine, ignition faults can cause trouble starting and warning lights. Some cases are resolved with engine control unit (ECU) updates or by replacing ignition components. These issues are worth addressing early because these cars can get expensive if a minor fault is ignored and allowed to snowball.
Mercedes A160 problems
The A160 badge has been used on older A-Class generations, so the common problems depend on the car's age. On older examples, the key is to be picky about condition and history. Make sure there’s evidence of proper servicing, and test every electrical feature, because age-related faults and repairs can quickly outweigh any bargain purchase price.
Find out what to look for when buying a used car.
Mercedes A180 problems
On diesel A180 models used for short trips, watch for DPF warnings; on petrol versions, look out for misfires or engine warning lights linked to ignition components. Across both, keep an eye out for any hesitation or harsh shifting.
Recalls
| Recall number | Date | Reason |
|---|---|---|
| R/2017/177 | 20.06.17 | The propellant mixing ratio in the igniters of the front passenger airbag assembly may not meet specification. If the airbag is required and activated it might not deploy or not completely deploy. This could increase the risk of injury to the occupants. |
| R/2017/096 | 20.06.17 | Where the car incurs severe engine damage resulting in the engine failing to turn over (engine seizure) and if the driver repeatedly attempts to start the engine despite the engine not cranking the very high electrical current could lead to overheating of the starting current limiter and the potential for a fire. |
| R/2017/179 | 20.06.17 | The connection fitting of the vacuum line to the brake booster is not to specification and my not be durable. If the connection fails the brake booster will no longer be supplied with vacuum. After a few brake applications the driver will have to apply additional pressure to the brake pedal to gain the appropriate braking effect. |
| R/2016/124 | 28.09.16 | A potentially faulty weld between the plate carrier and the hub of a clutch could be faulty/cracked and could fail. This can cause limp-home mode to be adopted or all drive to be lost. As a result the risk of a collision is heightened. |
| R/2015/259 | 21.01.16 | The high pressure fuel lines have not been manufactured to the correct specification which over time can lead to crack formation and fuel leaking. Fuel escaping in the presence of an ignition source could lead to fire. |
| R/2015/210 | 19.11.15 | The camshaft could break and damage the engine due to it not being manufactured to the correct specification. If the condition occurs it will lead to a sudden loss of drive thereby increasing the risk of a collision. |
| R/2015/145 | 12.08.15 | Certain fuses in the passenger's footwell may not have been fitted correctly. This may adversely affect the instrument cluster windscreen wipers and the passenger seat occupancy recognition system. In certain conditions this may cause the passenger's air bag not to deploy in an accident. |
| R/2015/099 | 14.07.15 | The drive shaft and the hub of the outer joint may separate. In very rare cases it cannot be excluded that the vehicle stops. The steering and braking system remain fully available to the driver. |
| R/2014/182 | 16.01.15 | On certain diesel engines the 'O' ring may not have been produced to the correct specification. This may allow oil to leak and contaminate the environment. If excessive oil is lost engine damage may occur. |
| R/2013/100 | 04.10.13 | On certain models fitted with the AMG seats it is possible that if the vehicle is involved in a side impact during very cold conditions below freezing the side cover for the back-rest member could become loose and cause injury. |
| R/2010/123 | 30.09.10 | It is possible on some fuel tanks that the vent pipe is not to specification. This can lead to a small leak into the charcoal canister and if not rectified can over a period of time result in a fuel leak. |
For earlier recalls, visit the government website here.
Mercedes A-Class 2005-2012 problems
1. Electrical faults
As these cars age, electrical niggles can crop up, such as intermittent warning lights, sensors playing up, or the cabin electrics behaving unpredictably.
What repair is needed for electrical faults, and how much does it cost?
The first step is a proper diagnostic scan and electrical testing to find the faulty sensor or wiring issue. Then it's a case of replacing or repairing the affected part. You can expect to pay an average of £61.85 for diagnostics.
2. CVT automatic gearbox issues
Some A-Class models were sold with a CVT automatic. If an automatic feels hesitant or jerky, or shows drivetrain/gearbox messages, it’s not something to ignore, because transmission faults can get expensive quickly.
What repair is needed for CVT automatic gearbox issues, and how much does it cost?
Start with a gearbox diagnostic to confirm whether it’s a control issue, sensor problem or internal gearbox fault. The average price of an automatic gearbox repair on FixMyCar is £562.22.
3. Clutch wear
On manuals, a worn clutch can show up as slipping under acceleration, a high bite point, juddering when pulling away, or difficulty engaging gears smoothly.
What repair is needed for clutch wear, and how much does it cost?
The usual fix is a full clutch replacement, which costs £680.75 on average when you book through FixMyCar.
4. Cooling system leaks
Cooling system leaks become more likely with age. If you notice a sweet smell in the cabin, damp patches under the vehicle, or the temperature creeping up, get it checked quickly, because overheating can cause serious engine damage.
What repair is needed for cooling system leaks, and how much does it cost?
The repair depends on the location and severity of the leak. Fixing a radiator leak costs an average of £214.14, according to our data.
Mercedes A-Class 2013-2018 problems
1. Automatic gearbox faults
Some A-Class automatics can develop gearbox issues that start as hesitant gear selection, sometimes with a warning light. In more severe cases, cars can go into limp mode.
What repair is needed for automatic gearbox faults, and how much does it cost?
Start with a diagnostic test to confirm whether it’s a software issue or a mechanical fault (a diagnostic test is typically around £60). An auto gearbox repair costs £562.22 on average on FixMyCar.
2. Electrical glitches
Electrical issues are reported on this generation, ranging from ECU cut-outs to faults that need a software update.
What repair is needed for electrical glitches, and how much does it cost?
A garage will usually run diagnostics first and then apply a software update, repair wiring/connectors, or repair the affected module. ECU repairs cost, on average, £129.98.
3. Oil leaks
Oil leaks are a known issue flagged on used models, so it’s worth checking for fresh oil around the engine bay and any burning oil smells after a drive.
What repair is needed for oil leaks, and how much does it cost?
The fix depends on the source (often a gasket or seal). Costs vary a lot with access, but budget roughly £200-£600, depending on where the leak is and how much labour is involved.
4. Failed shock absorbers
Some owners report suspension problems, including shock absorber failure. Any knocking over bumps, uneven tyre wear, or unresponsive handling is worth checking before it gets worse.
What repair is needed for failed shock absorbers, and how much does it cost?
A mechanic will typically replace the worn shocks (usually in pairs on the same axle), then check wheel alignment. Replacing a car's front shock absorbers costs £430.68 on average.
Mercedes A-Class 2018-present problems
1. Electrical faults
This generation commonly suffers from electrical issues, including faulty sensors, infotainment glitches and persistent warning lights. If you’re buying a used model, make sure the screen behaves normally (no freezing or reboots), driver aids work as expected, and there are no recurring warnings on the dash.
What repair is needed for electrical faults, and how much does it cost?
The first step is diagnostics (£61.85), then it’s usually a software update or replacing the failed part.
2. Automatic gearbox faults
On W177 cars, both manuals and automatics can have gearbox issues, but with the automatic, you’ll typically see a prominent warning message and a drop into limp mode with restricted gear selection.
What repair is needed for auto gearbox faults, and how much does it cost?
You’ll need a diagnostic scan first to pull the fault codes; the fix could range from a simple sensor replacement to a much bigger repair. Fixing an automatic gearbox costs £562.22 on average, according to our data.
3. DPF blockages
If a diesel A-Class is mainly used for short trips, it’s more likely to bring up a DPF warning because the system can’t regenerate properly. Frequent warnings or reduced power shouldn’t be ignored.
What repair is needed for DPF blockages, and how much does it cost?
A garage will first confirm the cause, then carry out a professional DPF clean if appropriate (average price: £207.06). More severe blockages may require a filter replacement, costing an average of £596.20.
4. Aircon not blowing cold air
Aircon issues can range from low refrigerant to a leak or a failed component. Always check that the system blows properly cold (and stays cold) on a test drive.
What repair is needed for aircon problems, and how much does it cost?
If the system just needs a regas, the average price on FixMyCar is £82.68. If parts need to be replaced (for example, due to a leak or a compressor-related fault), repairs can cost £500-£1,000+, depending on the vehicle and the extent of the work. Replacing an air conditioning compressor costs £424.27 on average, according to our data.
Years to avoid
There aren’t any single bad years to avoid across the A-Class range. Reliability varies much more by generation, engine and maintenance than by one registration year.
However, we recommend giving some versions extra checks before purchasing:
2005-2008 (earlier W169 cars): the later 2008-2012 versions have already had many faults ironed out, so earlier examples are the ones to be more cautious with. Check the history and condition very carefully.
2015-2017 (late W176 facelift): some owners reported gearbox issues that worsen over time and bring on warning lights, plus occasional ECU/ignition-related issues. Prioritise a smooth test drive, no warnings, and evidence that any faults have been properly fixed.
Here are the things to look out for when buying a used car.
Rule of thumb: you’ll avoid more headaches by skipping poorly maintained automatics and short-trip diesels with warning lights than by trying to dodge one specific registration year.
Is the Mercedes A-Class reliable?
In the 2024 What Car? Reliability Survey, the 2018-present A-Class did very well in the family car class. Petrol models came in 15th place out of 29, while hybrid versions came in second place, with a score of 98.7%. Unfortunately, Mercedes as a brand fared poorly, ranking 22nd out of 31 manufacturers, with an overall score of 89.7%.
By contrast, the reliability of the 2013-2018 A-Class is poor. In an earlier survey by What Car?, the petrol version came in 19th place out of 27 cars, while the diesel was almost at the bottom of the pack in 25th place. Mercedes was ranked 26th out of 31 manufacturers.
Overall, the A-Class is a bit of a mixed bag. Newer cars are much more reliable - especially the hybrids - but older models don’t have the same reputation. If you’re buying used, choose based on condition and history first, and be extra cautious with older diesels and any automatic showing warning lights or hesitant gear shifts.
If you found this guide helpful, you might also like:
- Related topics:
- Common Problems
- Mercedes
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.