What goes wrong, what it costs, and what to check before you buy a used Mercedes-Benz A Class.
The Mercedes-Benz A Class occupies a niche position on the UK market.
We track 5 known issues across the Mercedes-Benz A Class range, including 1 rated as safety-critical. Knowing which variants and configurations to approach with caution can save you from expensive surprises after purchase.
Found a Mercedes-Benz A Class? Enter the reg to see which of our 5 known issues apply to that exact car, plus full MOT history and mileage checks.
W168 (1997–2004) — Petrol options included the 1.4 A140, 1.6 A160, 1.7 A170, with 1.7 CDI on the diesel side. Our database flags 4 known issues on this generation, 1 of which are rated as safety-critical. The most significant concern is Brake flexible hose deterioration (£150–£300 to address).
W169 (2004–2012) — Petrol options included the 1.5 A150, 1.6 A160, 2.0 A200, with 2.0 CDI on the diesel side. Our database flags 5 known issues on this generation, 1 of which are rated as safety-critical. The most significant concern is Brake flexible hose deterioration (£150–£300 to address).
W176 (2012–2018) — Petrol options included the 1.5 A150, 1.6 A160, 2.0 A200/A250, with 1.8 CDI, 2.1 CDI on the diesel side. Our database flags 4 known issues on this generation, 1 of which are rated as safety-critical. The most significant concern is Brake flexible hose deterioration (£150–£300 to address).
A-Class models show severe brake hose deterioration at 153.5 times the fleet average failure rate, with over 33,000 MOT failures recorded across all variants. The flexible brake hoses connecting the rigid brake lines to the calipers suffer from internal delamination and external cracking, particularly where they flex during steering lock. This is a critical safety issue as hose failure results in complete brake circuit loss on the affected corner.
Complete brake hose failure results in total loss of braking on that wheel corner, creating dangerous braking imbalance and extended stopping distances. The car should not be driven if hose deterioration is suspected. Professional brake hose replacement on all four corners is typically required as they age together.
Check brake disc condition for lipping or scoring. Test braking at moderate speed for pulling to one side or vibration through the steering wheel. Review MOT advisories for brake-related items.
Mercedes diesel particulate filters on A-Class CDI models block frequently due to short urban journeys preventing proper regeneration cycles. The This affects all diesel variants but is particularly severe on the 1.7 CDI engine in the W169 generation. Blocked DPF triggers limp mode and eventually requires expensive replacement or professional cleaning.
A completely blocked DPF puts the car into limp mode with severely restricted performance. Professional DPF cleaning costs £200-400 but may not restore full function on heavily contaminated filters. Complete DPF replacement costs £1,200-2,000 plus fitting. The car remains driveable in limp mode for essential journeys only.
Ask about the car's typical usage — short urban journeys prevent DPF regeneration. Check for DPF warning lights and ask about any previous regeneration issues. A forced regeneration at a garage costs far less than a DPF replacement.
The steering column top bearing on W168 and W169 A-Class models develops excessive radial movement at 57.9 times the fleet average. This bearing supports the steering wheel end of the column and when worn creates dangerous free play in the steering. The problem is particularly pronounced on early W168 models where the bearing design was subsequently improved. Excessive play makes precise steering control difficult and creates an MOT failure.
Severe bearing wear creates dangerous steering instability and will result in MOT failure. The steering column assembly typically requires replacement as the bearing is not separately serviceable. Complete loss of steering control is possible if the bearing collapses entirely. The car should not be driven if significant play is detected.
During the test drive, check the steering for excessive play, vibration or pulling to one side. Listen for groaning or whining when turning the wheel at low speed. Power steering fluid level and condition should be checked on hydraulic systems.
A-Class models experience shock absorber failure at 50.2 times the fleet average, with the problem worsening over time according to MOT data. The front shock absorbers lose damping effectiveness due to internal seal failure, causing oil leakage and complete loss of damping control. This affects ride quality severely and creates dangerous handling characteristics, particularly during braking and cornering where the car becomes unpredictable.
Failed shock absorbers create dangerous handling characteristics, particularly poor braking stability and unpredictable cornering behaviour. The car remains roadworthy for essential journeys but should not be driven enthusiastically. Shock absorbers are typically replaced in pairs to maintain handling balance.
Listen for knocking, clunking or rattling over bumps during the test drive. Inspect the underside for corroded or cracked suspension components. Check the MOT history for suspension-related advisories, which often predict future failures.
Universal joint and flexible coupling failures occur at 208.5 times the fleet average on A-Class models, with over 900 MOT failures recorded. This primarily affects the outer CV joints on the front driveshafts which suffer from boot deterioration allowing contamination of the joint. The problem is exacerbated by the A-Class's compact packaging which places stress on the driveshaft angles, particularly during full-lock manoeuvres.
Worn CV joints create clicking noises initially but can progress to complete joint failure and loss of drive to that wheel. A completely failed outer CV joint makes the car undriveable. Inner joint failure is less common but more expensive to repair. Joint replacement typically includes the entire driveshaft assembly.
Listen for clunking or vibration from underneath when pulling away or changing direction. Check for play in the driveshafts by rocking the car in gear with the handbrake on. Worn CV boots are a telltale sign — look for grease splatter around the inner wheel arch.
For the full breakdown of all 5 tracked issues with repair costs, see the Mercedes-Benz A Class common problems page.
Routine servicing (oil and filter change every 16k miles) typically costs £80–£150 at an independent garage.
See the full Mercedes-Benz A Class service schedule for every interval and cost breakdown.
The Mercedes-Benz A Class has some well-documented weak points, including 1 safety-critical issue that demand careful checking. The right example, properly maintained, can still be a sound purchase — but cutting corners on the pre-purchase inspection is not advisable.
Before committing, check the car's full MOT history, verify the service record is complete, and if possible arrange a specialist inspection. Enter any registration into our free report to see the complete picture.
Get Car Wise maintains a database of known mechanical issues for every popular car on UK roads, tracking the faults that owners, specialists and DVSA data reveal.
When you run a report on a specific Mercedes-Benz A Class, we cross-reference the exact variant, engine and age against our database of 5 known issues. Combined with full MOT history analysis, mileage verification and DVLA data, you get a complete picture before viewing.
Enter the registration for MOT history, mileage verification, known faults for that exact variant, and a Get Car Wise Score.
This guide was compiled from independent expert reviews, DVSA MOT data, specialist workshops and our own database of 5 known Mercedes-Benz A Class issues. We are not affiliated with any source listed.