Fault File
All models / All cars / Coupés, convertibles & GT / BMW 4 Series

BMW 4 Series

All generations and engines together · 119,232 MOT tests in the 2025 data · typical mileage at age 7: 63k

First-time failure at age 7
15.2%
Across 17,688 tests. The average across all tracked models is 19.5%.
Rank at age 7
59 of 239
1 = lowest failure rate among the models tracked.
Typical mileage at age 7
63k miles
Check the mileage view below; low-mileage models can look better by age than they are.

Generation

Split by first-registration year. Cars registered in a changeover year can belong to either generation.

How this model wears

BMW 4 SeriesClass 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. 71,950 tests in this band.

A suspension pin, bush or joint excessively worn
Advisory
4.7%class 5.9%
Play in steering rack inner joint(s)
Advisory
3.9%class 1.1%
A shock absorber damaged to the extent that it does not function or showing signs of severe leakage
Advisory
3.2%class 2.3%
Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road users
Advisory
2.6%class 2.4%
A shock absorber damaged to the extent that it does not function or showing signs of severe leakage
Fail
1.1%class 0.4%
A wheel badly distorted or wear between wheel and hub at spigot mounting
Advisory
0.8%class 0.6%
A suspension pin, bush or joint excessively worn
Fail
0.7%class 0.9%
Excessive fluctuation in brake effort through each wheel revolution.
Advisory
0.7%class 0.6%

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
29.3%class 22.9%
A brake lining or pad worn below 1.5mm
Advisory
9.2%class 8.7%
Brake disc or drum excessively weakened, insecure or fractured
Advisory
8.7%class 10.1%
A tyre seriously damaged
Advisory
7.0%class 13.4%
A tyre seriously damaged
Fail
3.8%class 2.0%
Brake disc or drum significantly and obviously worn
Advisory
3.2%class 3.4%
A tyre cords visible or damaged
Fail
3.0%class 1.2%
Tyre tread depth not in accordance with the requirements
Fail
2.5%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.

EGR cooler failure on 420d/425d diesels

Diesel only

Some diesel 4 Series cars needed a new EGR cooler, and BMW ran a recall covering affected diesel engines over an overheating and cracking risk. Owners report the car being off the road for weeks waiting on the part. If the recall stamp isn't in the history, or the cooler has already been replaced once, budget for it happening again down the line. Petrol cars aren't affected.

Reported on 420d/425d diesels · check the recall was carried out · sources: Honest John owner reports

Timing chain rattle on the turbo petrol engines

Emerging

A rattle from the front of the engine on cold start-up on the 420i/428i/430i's turbo four-cylinder is a recurring owner complaint, usually put down to a stretched chain or worn guides. It tends to show up from around 80,000 miles, more so on cars that have gone the full 20,000-mile service interval rather than an annual oil change. Left alone, a full chain and guide job runs into four figures. No UK-specific manufacturer bulletin found, so this is one to listen for rather than assume.

Reported from around 80k miles · sources: Honest John owner reports, general BMW turbo-four owner discussion

Early clutch and dual-mass flywheel wear

Manual only

On manual cars the clutch and dual-mass flywheel can wear out well before you'd expect, one documented case needed both replaced at just 20,000 miles. It shows up as a shudder pulling away or a bite point that's gone high and vague. A full clutch and DMF replacement is one of the bigger bills on this car. Doesn't apply to the automatic, which uses a torque converter instead of a clutch.

Reported from 20k miles · sources: Honest John owner reports

Front End Module (FEM) failure

Emerging

The FEM handles lighting, power steering assist and other core electrics near the front of the car, and there are owner reports of it failing outright, lights, power steering and dash all cutting out together while driving. It doesn't appear to be something BMW has acknowledged as a pattern, and at least one owner was quoted close to £1,000 for diagnosis and a replacement module with no dealer contribution. Not common, but expensive and unnerving when it happens.

Documented case with no dealer goodwill offered · sources: Honest John owner reports

Front-end knocks, rumbles and vague steering

Partly in the MOT data

Owners describe a loose, vague feel through the steering along with a rumbling or knocking noise from the front, worse on turns, that in at least one case a dealer traced to a loose steering joint rather than something simple like a worn bush. The measured MOT data lines up with this: suspension is the standout failure category for this model. It doesn't tell you which specific part is at fault, so any rumble on a test drive is worth chasing down properly rather than writing off as road noise.

Reported across coupe and convertible · sources: Honest John owner reports, measured MOT fault data

Convertible roof seals and dropping windows

Convertible only

On the folding hard-top convertible, the seal where the roof meets the body can let in water and wind noise, and owners report it coming back after a dealer clean and reseal rather than being fixed for good. Separately, the side windows, which drop slightly to clear the frame as the door opens, can start doing this on their own with the roof up. Neither is a quick fix if it's the seal itself rather than just dirt in the mechanism. Doesn't apply to the coupe or Gran Coupe.

Reported at various ages · sources: Honest John owner reports

Viewing one? Ask this

Built from the two sections above.

Check the V5C and service book for an EGR-related recall stamp on diesel cars. If it's missing, the recall work may not have been done and the cooler could still fail.
Start a petrol turbo model dead cold and listen to the front of the engine for the first few seconds. A rattle lasting more than a second or two points to a worn timing chain or guides.
On a manual, pull away from a dead stop a few times and feel the clutch bite. A high, vague bite point or a shudder means the clutch and dual-mass flywheel are wearing out.
Turn the wheel lock to lock at walking pace and drive over a speed bump. Rumbling, knocking or vague steering points to the front-end wear that shows up heavily in this model's MOT failures.
Check the dash lights and power steering assist stay live through a full ignition cycle. A total electrical dropout, lights and steering assist together, suggests the FEM module is on its way out.
On a convertible, cycle the roof up and down twice and check the carpet and parcel shelf for damp. Water staining means the roof seal is leaking, possibly already 'cleaned' rather than actually fixed.
Pull the full service history and check the intervals were closer to annual than the full 20,000-mile mark. Stretched oil-change intervals are linked by owners to faster timing chain and general engine wear.

Others in its class

Same segment (Coupés, convertibles & GT), best MOT record first. Compare before you shortlist.

How it compares

Head to head with the other popular cars in its class on reliability and common faults.