Fault File
All models / All cars / Saloons & estates / Hyundai i40

Hyundai i40

All generations and engines together · 19,840 MOT tests in the 2025 data · typical mileage at age 7: 89k

First-time failure at age 7
19.9%
Across 1,967 tests. The average across all tracked models is 19.5%.
Rank at age 7
147 of 239
1 = lowest failure rate among the models tracked.
Typical mileage at age 7
89k miles
Check the mileage view below; low-mileage models can look better by age than they are.

How this model wears

Hyundai i40Class average, all tracked models

Known issues

Measured

Computed from DVSA MOT results, all of Great Britain, 2025. Nothing here is opinion.

What testers flag

Share of tests where each item was recorded. The dark tick is the class average across all tracked models; bars are scaled within each group.

Faults with the car itself

The rows that judge the model rather than its keeper. 8,878 tests in this band.

Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road users
Advisory
4.5%class 2.0%
Brake pipe damaged or excessively corroded
Advisory
4.4%class 1.9%
A suspension pin, bush or joint excessively worn
Advisory
4.2%class 6.6%
A headlamp or light source missing, inoperative or more than ½ not functioning in the case of LED
Fail
2.9%class 0.8%
Significant brake effort recorded with no brake applied indicating a binding brake
Advisory
2.3%class 0.7%
Excessive fluctuation in brake effort through each wheel revolution.
Advisory
1.6%class 0.6%
Play in steering rack inner joint(s)
Advisory
1.6%class 1.1%
Engine MIL illuminated indicating a malfunction
Fail
1.1%class 0.4%
Brake pipe damaged or excessively corroded
Fail
1.0%class 0.2%

Wear, upkeep and luck

Tyres, pads and stone chips say more about how the car was driven and maintained than about how it was built.

Tyre tread depth not in accordance with the requirements
Advisory
32.2%class 22.9%
A brake lining or pad worn below 1.5mm
Advisory
14.2%class 8.7%
Brake disc or drum excessively weakened, insecure or fractured
Advisory
11.3%class 10.1%
A tyre seriously damaged
Advisory
11.2%class 12.7%
A brake lining or pad worn below 1.5mm
Fail
3.7%class 1.6%
Brake disc or drum significantly and obviously worn
Advisory
3.5%class 3.4%
Number plate inscription missing or illegible
Advisory
3.2%class 1.5%
Tyre tread depth not in accordance with the requirements
Fail
2.8%class 2.2%

Unconfirmed issues

Reported

Owner folklore from forums and the motoring press. Most of it never shows up in an MOT, which is why this section exists at all.

Manual clutch wear and hard-to-select gears

Emerging

Owners of manual i40s report clutch trouble surfacing well before you'd expect normal wear, with a supplier change around 2014 blamed for a run of cars needing early replacement (some owners were left waiting on backordered parts). The symptom is notchy or resistant gear selection, especially reverse, first and second, sometimes needing more than one dip of the pedal. No manufacturer TSB or recall covers this; a clutch and dual-mass flywheel job is a proper bill, roughly £500-£1,200 depending on the garage.

Reported from around 40-60k miles · sources: Honest John, AutoInsider clutch reports

DCT automatic hesitation and judder from standstill

Automatic (DCT) only

The dual-clutch automatic gets recurring reports of jerky, delayed changes and a shunt pulling away from a stop, with owners noting it gets worse from roughly 50,000 to 75,000 miles. One early case even had the car refuse to select D, N or R out of Park. There's no public recall for it; a mechatronic unit or clutch-pack repair on this type of gearbox typically runs well over £1,000. Doesn't affect manual cars.

Reported 50-75k miles · sources: Honest John, AutoDoc

DPF regeneration failures on the diesel

Emerging

Short-run driving on the CRDi diesels brings on the usual DPF trouble: a check-engine light that clears for a few dozen miles then comes straight back, and in worse cases visible smoke on start-up. It's turned up even after fuel pump or injector work, which points to driving pattern and filter condition rather than one faulty part. No TSB was found; sorting it ranges from a forced regeneration for not much money to a four-figure filter replacement if it's badly clogged.

Mostly higher-mileage, short-trip cars · sources: Honest John, Hyundai Forums (1.7 CRDi threads)

Rust above the windscreen and along roof/door seams

Disputed

Bubbling paint and rust above the windscreen and along roof and door-top seams gets mentioned often enough by owners to look like a real pattern, with one owner of a 2016 car calling it 'a common problem on both sides.' Dealers have pushed back on some claims, putting it down to stone chips rather than a paint or seam defect, so whether it's a manufacturing weak spot or bad luck is genuinely argued over. Cost to fix varies hugely, from a local touch-up to a full panel respray.

Seen from around 5 years old · sources: Honest John, owner forum reports

Brake booster failure (recall-covered build window)

Partly in the MOT data

A genuine safety recall covers i40s built between December 2018 and May 2019 for a brake booster that can fail, reducing braking assistance and stopping performance; Hyundai issued a free fix for affected cars. The measured MOT data for this model already flags brakes as the standout failure area, so this recall lines up with a real, above-average pattern rather than being an isolated scare. Check the VIN against the recall register before buying a car from that build window.

Affects Dec 2018-May 2019 build · sources: Hyundai/DVSA recall record, car-recalls.co.uk

Idle Stop & Go battery giving up early

Idle Stop & Go cars only

Cars fitted with Idle Stop & Go can develop a battery that reads as too weak for the system even though it still starts the car fine day to day, causing ISG to switch itself off. One owner was quoted around £329 for a replacement AGM battery, and in at least one case the dealer couldn't get stop-start working again afterwards. It's an expense and a nuisance rather than a breakdown risk, and only applies to trims and years with ISG fitted.

Reported from around 4-5 years old · sources: Honest John, general ISG battery guidance

Viewing one? Ask this

Built from the two sections above.

On a manual car, work through every gear including reverse and first from a standstill. Notchy or resistant changes needing extra clutch dips point to the known clutch wear issue.
On an automatic (DCT) car, pull away repeatedly in stop-start traffic. Any shunt, hesitation or delayed engagement from standstill is the DCT judder fault, not the driver.
Ask when the car last needed a DPF regeneration or clean, and how it's mostly been driven. Frequent short trips plus a history of DPF warning lights means the filter is due expensive attention.
Check the vehicle's recall status against the VIN before handing over money. Cars built December 2018 to May 2019 may carry an unfixed brake booster recall.
Look closely above the windscreen, along the roof seams and door tops for bubbling paint. Early rust here is a known complaint and can be costly to put right properly.
If the car has Idle Stop & Go, sit at a stop and see if the engine cuts and restarts cleanly. A system that won't engage or restarts sluggishly usually means a tired stop-start battery, £300+ to replace.

Others in its class

Same segment (Saloons & estates), best MOT record first. Compare before you shortlist.