Mercedes Benz Gla MOT Failures
An analysis of 289,860 real DVSA MOT tests on the Mercedes Benz Gla — what fails, how often, and how that compares to every other car on UK roads. Generations covered: X156 (2014–2020).
Where the Mercedes Benz Gla fails its MOT
The single biggest MOT failure point on the Mercedes Benz Gla is anti-roll bar links worn — this model is 10 times more likely to fail on this item than the average car on UK roads. That makes it worth watching for anyone buying or owning this model. Across 289,860 MOT tests, 0.39% of all Mercedes Benz Gla tests recorded this as a failure.
Suspension failures typically mean worn bushes, drop links, or dampers. These affect handling and tyre wear. Budget £150–£400 per corner at an independent garage for full suspension overhaul.
Other notable weak points include transmission shaft flexible coupling deteriorated (8.6x the fleet average), tyre wear or damage (8.1x the fleet average), brake lining or pad worn down to wear indicator (6.5x the fleet average), and steering lock missing or not functioning (11x the fleet average). These ratios compare the Mercedes Benz Gla's failure rate on each item against the national average for all cars tested — a ratio of 10x means this model fails ten times more often than a typical car.
The failures span 6 categories: Suspension, Bodywork, Tyres, Brakes, Steering and others. If you're inspecting a Mercedes Benz Gla before purchase, these are the areas to focus on — and if any have been flagged as advisories on a previous MOT, they're likely to become failures in the near future.
How failures change with mileage
The Mercedes Benz Gla's weak points shift as the car covers more miles. Understanding these patterns helps you know what to expect — and what to budget for — at each stage of ownership.
Under 60,000 miles
At this mileage, most failures are either design-related or caused by age rather than wear. Components like bushes and drop links may not have been replaced yet, and original-fit parts can deteriorate even on low-mileage cars that spend a lot of time sitting.
For the Mercedes Benz Gla specifically, the DVSA data shows the most common failures at this mileage are anti-roll bar links worn (10x the average) and brake fluid below minimum mark (9.5x). brake fluid significantly below minimum mark (7.3x) and brake lining or pad worn down to wear indicator (6.5x) also appear frequently.
60,000 to 100,000 miles
This is where routine wear items start to show up. Brake components, tyres, and exhaust parts have done serious work by this point. Cars that have been well serviced will show fewer of these failures — this mileage band is where good maintenance really separates the well-kept from the neglected.
For the Mercedes Benz Gla specifically, the DVSA data shows the most common failures at this mileage are steering lock missing or not functioning (11x the average) and tyre wear or damage (7.2x). transmission shaft flexible coupling deteriorated (6.3x) and anti-roll bar links worn (6.1x) also appear frequently.
Over 100,000 miles
High-mileage cars accumulate failures across multiple systems. The key question isn't whether things will need doing — they will — but whether the car has been maintained well enough to keep on top of them. Look for a consistent service history and recent MOT passes with minimal advisories.
For the Mercedes Benz Gla specifically, the DVSA data shows the most common failures at this mileage are tyre wear or damage (8.1x the average) and transmission shaft flexible coupling deteriorated (5.6x). anti-roll bar links worn (5.0x) and emissions failure (5.0x) also appear frequently.
The shift from anti-roll bar links worn at lower mileages to tyre wear or damage at higher mileages is typical — early failures tend to be design or factory-related, while high-mileage failures reflect accumulated mechanical wear. A car that's been well maintained will usually dodge the worst of both.
Known issues beyond the MOT
An MOT only tests roadworthiness at a single point in time — it won't catch developing faults, intermittent problems, or issues that haven't yet reached the failure threshold. These are the issues that Mercedes Benz Gla specialists and owners flag most frequently, drawn from manufacturer technical bulletins, workshop data, and verified owner reports.
Excessive brake fluid consumption Major
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. Affects X156; typical independent garage repair cost is £300–£800.
Suspension joint dust cover deterioration
The GLA suffers premature deterioration of suspension joint dust covers, with failures at 7.8x the fleet average. Affects X156; typical independent garage repair cost is £80–£200.
Premature brake pad wear
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. Affects X156; typical independent garage repair cost is £120–£250.
Engine management light (diesel variants)
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. Affects X156; typical independent garage repair cost is £150–£600.
For the complete picture — including repair costs across independent, specialist, and dealer garages — see the full Mercedes Benz Gla common problems breakdown.
What to check before buying a Mercedes Benz Gla
Based on the MOT failure data and known issues above, here's what to prioritise when inspecting a Mercedes Benz Gla:
Suspension — check for anti-roll bar links worn. Bodywork — check for transmission shaft flexible coupling deteriorated. Tyres — check for tyre wear or damage. Brakes — check for brake lining or pad worn down to wear indicator, brake fluid below minimum mark, brake fluid significantly below minimum mark.
Beyond the MOT items, ask specifically about excessive brake fluid consumption and suspension joint dust cover deterioration. These won't show up on a standard MOT but can be expensive to fix — repairs start from £300. A specialist pre-purchase inspection is worth the investment on this model.
Always check the car's full MOT history for patterns — recurring advisories often become failures within 12 months. And verify the service history to confirm maintenance has been kept up to schedule. Enter any reg into our free car check to see the complete picture.
Looking at a specific Mercedes Benz Gla?
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Mercedes Benz Gla MOT FAQs
What are the most common MOT failures on a Mercedes Benz Gla?
Based on 289,860 DVSA MOT tests, the most common failure is anti-roll bar links worn — at 10x the national fleet average. Other frequent failures include transmission shaft flexible coupling deteriorated and tyre wear or damage.
Is the Mercedes Benz Gla reliable based on MOT data?
The Mercedes Benz Gla has 9 MOT failure categories above the fleet average. Specialists also flag excessive brake fluid consumption as a concern. A pre-purchase inspection and service history check are recommended.
What MOT failures should I expect at high mileage?
Above 100,000 miles, the Mercedes Benz Gla most commonly fails on tyre wear or damage and transmission shaft flexible coupling deteriorated. Under 60,000 miles, the main issues are anti-roll bar links worn and brake fluid below minimum mark.
How do I check a Mercedes Benz Gla's MOT history?
Enter the registration number into our free car check above. You'll see every MOT test result, advisories and failures, mileage readings, write-off status, and finance checks.
MOT failure data sourced from DVSA bulk test records via data.gov.uk. Ratios compare this model's failure rate against the national fleet average. Known issues sourced from manufacturer bulletins, specialist workshops, and verified owner reports.