Compact premium crossover with sharp styling and MBUX tech
The GLA bridges the gap between hatchback and SUV in Mercedes' UK lineup. First-generation X156 models (2014-2020) now start from £7,000-£11,000 and have largely stopped depreciating, losing just £500-£1,000 annually. The second-generation H247 (2020+) brought significantly more cabin space, the MBUX infotainment system, and improved ride quality. AMG Line trim dominates the used market and holds value best.
We track 5 known issues across the Mercedes-Benz GLA range, with 1 classified as significant. Knowing which variants and configurations to approach with caution can save you from expensive surprises after purchase.
Found a Mercedes-Benz GLA? Enter the reg to see which of our 5 known issues apply to that exact car, plus full MOT history and mileage checks.
X156 (2014–2020) — Petrol options included the GLA 200, GLA 250, with GLA 220 CDI/d on the diesel side. We track 5 known issues on this generation, with 1 classified as significant. The most significant concern is Excessive brake fluid consumption (£300–£800 to address).
The GLA shows abnormally high rates of brake fluid falling below minimum levels, with MOT data showing failures at 9.5x the fleet average on some variants. This suggests either external leaks from brake lines or internal consumption through worn brake components. The issue affects cars from new, indicating a design or manufacturing concern rather than normal wear. Low brake fluid triggers ESP and ABS warning lights and can lead to brake system failure.
Brake system failure can occur without warning if fluid levels become critically low. External leaks typically require brake line replacement at £300-600. Internal consumption may indicate master cylinder or brake servo issues costing £800-1500. The car should not be driven if brake fluid levels cannot be maintained.
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.
The GLA suffers premature deterioration of suspension joint dust covers, with failures at 7.8x the fleet average. These rubber boots protect ball joints and track rod ends from dirt and water ingress. When they split or detach, contamination accelerates joint wear and leads to MOT failures. The issue affects multiple suspension components across all engine variants and appears to worsen over time, suggesting material quality concerns.
Split dust covers allow contamination of suspension joints, leading to premature wear and eventual joint replacement at £200-400 per side. This is primarily an MOT failure issue rather than a safety concern, but neglected joints will require more expensive replacement rather than simple cover renewal.
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.
MOT data shows the GLA reaches brake pad wear indicators at 6.6x the fleet average, particularly on 1.6L petrol variants at low mileage. This suggests either aggressive brake pad compounds, insufficient cooling, or brake system imbalance causing uneven wear. The issue affects cars from very low mileage, indicating design factors rather than normal wear patterns.
Worn brake pads require replacement at £150-300 for front and rear sets. If not replaced promptly, the metal backing plates score the brake discs, requiring disc replacement at additional cost of £200-400. Completely worn pads can cause brake failure.
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.
The 2.1L diesel GLA shows engine management light failures at This typically indicates emissions system faults such as EGR valve carbon build-up, DPF regeneration problems, or lambda sensor failures. The pattern across all mileage bands suggests design vulnerabilities in the emissions control system rather than normal component wear.
Emissions system faults can cause MOT failures and reduced fuel economy. EGR valve cleaning costs £200-400, DPF regeneration or replacement £800-2000, and lambda sensor replacement £150-300. The car remains driveable but may enter reduced power mode.
Check for any engine warning lights on the dashboard. Ask about the car's MOT emissions history — repeated failures suggest underlying issues. A pre-purchase diagnostic scan is especially worthwhile to check for stored emissions fault codes.
The GLA experiences CV joint boot failures at 2.6x the fleet average, primarily affecting the outer joints on the driveshafts. These rubber boots protect the constant velocity joints from dirt and moisture while containing the joint grease. When they split, the joints become contaminated and wear rapidly, eventually requiring complete driveshaft replacement.
Split CV joint boots allow grease to escape and contamination to enter, leading to joint wear and eventual driveshaft replacement at £300-500 per side. Boot replacement alone costs £100-200 per joint if caught early before joint damage occurs.
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 GLA common problems page.
Based on 338k real DVSA MOT tests, the Mercedes-Benz GLA fails more often than average on several items. The biggest outlier is steering lock missing or not functioning at 11x the fleet average, followed by anti-roll bar links worn (10x).
When viewing a specific car, check its MOT history for recurring advisories in these categories. See the full Mercedes-Benz GLA MOT failure breakdown for data at every mileage point.
Routine servicing (oil and filter change every 16k miles) typically costs £120–£180 at an independent garage.
The bigger-ticket items to budget for include automatic transmission fluid (£200–£300).
See the full Mercedes-Benz GLA service schedule for every interval and cost breakdown.
The Mercedes-Benz GLA is a reasonable used buy provided you check for the issues outlined above. None of the problems we track are insurmountable, but they do reward buyers who inspect thoroughly and verify the service history before committing. 2020-2022 second-generation (H247) models are the best overall, with vastly improved interior space and MBUX tech. For budget buyers, 2019 X156 facelift models offer the most refined first-gen experience. Avoid 2015 and 2017-2018 models due to higher rates of brake and electrical faults. The GLA 200d is the sweet spot for running costs; GLA 250 4MATIC suits those wanting petrol power.
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 GLA, 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 GLA issues. We are not affiliated with any source listed.