Infiniti Q30 MOT Failures

An analysis of 10,673 real DVSA MOT tests on the Infiniti Q30 — what fails, how often, and how that compares to every other car on UK roads. Generations covered: H15 (2015–2019).

Where the Infiniti Q30 fails its MOT

The single biggest MOT failure point on the Infiniti Q30 is headlight fault — this model is 6.8 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 10,673 MOT tests, 0.75% of all Infiniti Q30 tests recorded this as a failure.

Lighting faults are usually straightforward to fix (bulbs, connectors, earth points) but can indicate deeper wiring issues on older cars. Check all lights including fog lamps, number plate lights, and dashboard warning lights.

Other notable weak points include light unit fault (27x the fleet average), anti-roll bar links worn (7.2x the fleet average), and excessive fluctuation in brake effort through e... (7.3x the fleet average). These ratios compare the Infiniti Q30'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 3 categories: Lights & Electrics, Suspension, Brakes. If you're inspecting a Infiniti Q30 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 Infiniti Q30'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 Infiniti Q30 specifically, the DVSA data shows the most common failures at this mileage are anti-roll bar links worn (6.3x the average) and headlight fault (5.4x).

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 Infiniti Q30 specifically, the DVSA data shows the most common failures at this mileage are light unit fault (27x the average) and excessive fluctuation in brake effort through e... (7.3x). headlight fault (6.8x) and headlight fault 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.

The standout failure at this mileage is anti-roll bar links worn at 7.2x the fleet average.

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 Infiniti Q30 specialists and owners flag most frequently, drawn from manufacturer technical bulletins, workshop data, and verified owner reports.

Premature brake disc wear (H15) Major

The Q30 suffers from accelerated brake disc wear compared to the fleet average, with MOT data showing failure rates 3.8 times higher than typical. Affects H15; typical independent garage repair cost is £200–£350.

Turbocharger actuator failure (H15) Major

The electronic turbocharger wastegate actuators on Q30 turbocharged engines (both petrol and diesel) can fail, causing loss of boost control. Affects H15; typical independent garage repair cost is £300–£600.

Suspension joint dust cover failure (H15)

The rubber dust covers protecting suspension ball joints and bushes deteriorate prematurely on the Q30, particularly on diesel variants which typically see higher mileage use. Affects H15; typical independent garage repair cost is £40–£80.

Engine management light - emissions system (H15)

Diesel Q30 models show elevated rates of MOT failure for illuminated engine management lights, occurring at Given the Mercedes-Renault platform sharing, this is likely related to EGR valve carbon build-up or diesel particulate filter issues typical of this engine family.. Affects H15; typical independent garage repair cost is £80–£400.

For the complete picture — including repair costs across independent, specialist, and dealer garages — see the full Infiniti Q30 common problems breakdown.

What to check before buying a Infiniti Q30

Based on the MOT failure data and known issues above, here's what to prioritise when inspecting a Infiniti Q30:

Lights & Electrics — check for headlight fault, light unit fault. Suspension — check for anti-roll bar links worn. Brakes — check for excessive fluctuation in brake effort through e....

Beyond the MOT items, ask specifically about premature brake disc wear and turbocharger actuator failure. These won't show up on a standard MOT but can be expensive to fix — repairs start from £200. 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.

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.