Fault File
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BMW Z4

All generations and engines together · 18,504 MOT tests in the 2025 data · typical mileage at age 7: 40k

Typical mileage at age 7
40k 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 Z4Class 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. 2,990 tests in this band.

Any fracture or welding defect on a wheel
Fail
3.3%class 0.1%
A shock absorber damaged to the extent that it does not function or showing signs of severe leakage
Advisory
2.0%class 2.3%
A spring or spring component fractured or seriously weakened
Fail
1.9%class 1.4%
Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road users
Advisory
1.8%class 2.4%
A suspension pin, bush or joint excessively worn
Advisory
1.6%class 6.7%
A wheel badly distorted or wear between wheel and hub at spigot mounting
Advisory
1.5%class 0.6%
A suspension component excessively damaged or corroded
Advisory
0.7%class 0.7%
A shock absorber damaged to the extent that it does not function or showing signs of severe leakage
Fail
0.5%class 0.4%

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
22.1%class 22.9%
A tyre seriously damaged
Advisory
13.6%class 13.4%
Brake disc or drum excessively weakened, insecure or fractured
Advisory
8.9%class 10.1%
A brake lining or pad worn below 1.5mm
Advisory
6.0%class 8.7%
A tyre cords visible or damaged
Fail
4.3%class 1.2%
A tyre seriously damaged
Fail
4.0%class 2.0%
Nail in tyre
Advisory
2.6%class 1.6%
Tyre tread depth not in accordance with the requirements
Fail
1.6%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.

Soft-top roof motor and pump water ingress (E85/E86)

Confirmed pattern

On the first Z4 (2003-2009 roadster), water gets into the hood motor mounted by the passenger B-pillar and kills it; on early cars the pump also sits in a plastic tray that fills with water and seizes. It shows up as the car gets into its later years regardless of mileage. A full motor replacement runs £900-1,400, the early pump seizure fix nearer £650, and BMW has been known to make a goodwill contribution even out of warranty, which is about as close to an acknowledgement as this gets.

Reported from around 5-8 years old · goodwill repairs from BMW dealers · source: Honest John

Kerbed and cracked wheels

Partly in the MOT data

Owners regularly report rims marked from kerbing, and on the E89 rear 19-inch wheels have cracked outright during a service, one repair coming in around £1,100. Low-profile tyres and firm suspension mean the car grounds out on speed humps, and rear springs have failed from the same impacts. This lines up with the measured MOT data for this model, where wheel-related failures are the standout fault; the forums pin more of the blame on kerbs and speed humps than the test data alone can confirm.

Reported across both generations · rear wheel crack repair ~£1,100 · source: Honest John

Electric power steering (EPAS) failure

Confirmed pattern

Owners on both generations report the electric power steering going sticky or jumpy, and on the E89 it has failed outright, in one case at 36,000 miles despite the car already having had a related recall carried out. When it goes, the same electrical backbone can also take out the parking brake, wipers, speedo and rev counter. A dealer EPAS repair has been quoted around £1,500.

Reported from around 30-40k miles · prior recall referenced · source: Honest John

DSC (stability control) module failure

Emerging

At least one owner reports the Dynamic Stability Control system failing outright as early as 31,000 miles, with a dealer bill around £2,000. It's nowhere near as widely reported as the roof or steering faults, so treat it as a possibility rather than a pattern, but it's an expensive one if the module or sensor pack does need replacing.

Reported from 31k miles, single case found · repair quoted ~£2,000 · source: Honest John

TPMS valve corrosion on run-flat wheels

Run-flat tyre cars only

Cars on run-flat tyres can suffer valve stem corrosion from a battery effect between the metal valve cap and the stem, triggering a false-looking tyre pressure warning. It doesn't touch cars on standard tyres with plastic caps, and swapping to plastic caps stops it recurring. Cheap to sort, but worth knowing why the light is on before you assume a puncture.

Run-flat equipped cars only · source: Honest John

Bluetooth battery drain and minor electrical niggles

Disputed

Leaving a phone paired without a full shutdown can leave the car hunting for the Bluetooth connection overnight and drain the battery, reported on both generations. Owners also mention the odd failed indicator stalk switch (around £600 to replace) and door mirror glass coming loose from its pod. None of it is safety-critical, and how often it actually happens versus normal old-car wear is something owners argue about.

Reported intermittently, mileage varies · source: Honest John

Viewing one? Ask this

Built from the two sections above.

With the roof up and down a couple of times, listen for the hood motor labouring, and check under the boot trim by the passenger B-pillar for damp or corrosion. A straining motor or a musty smell there points to water ingress and a £900+ repair.
Walk round all four wheels and check the rears closely for hairline cracks, not just kerb scuffs. A cracked rim, especially on an E89 with 19s, means an immediate replacement and ties to this model's real MOT wheel-failure pattern.
Turn the wheel lock to lock at a standstill, then again on the move at low speed. Sticky, jumpy or inconsistent weight in the steering points to EPAS wear or failure.
Check the MOT history and any service invoices for repeat DSC, ABS or stability-control warning lights. A DSC fault that keeps coming back means the module or sensor is on its way out, a job that can run to £2,000.
If the car is on run-flat tyres, check for a lit TPMS warning with the engine running. A lit warning can mean corroded valve stems rather than an actual puncture.
Pair your phone, lock the car without disconnecting it, then check the battery the next day if you can. A flat battery from Bluetooth hunting is a known but minor gremlin, not a sign of a bigger fault.
Test every switch, indicators included, and give the door mirror glass a gentle push. A failed indicator stalk or loose mirror glass are cheap-ish but genuinely common niggles on this model.

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