Model Reports 4 min read Updated 18 Oct 2026

BMW Z4 2008: reliability & common MOT faults

In 2025, 69 in every 100 first MOTs on a 2008 BMW Z4 were passes. Most common reason for a fail: Petrol engine warning light.

Summary

A 2008 BMW Z4 passed first time about 7 in every 100 less often than the average of the 2007 and 2009 model years.

At a glance

How 1,674 first tests went in 2025.

Passed first time
69 in every 100
Did not pass first time
31 in every 100516 failed first-attempt tests
The typical car
17 yearsabout 80,422 miles
First tests counted
1,674

What failed most often

  1. Petrol engine warning light15 in every 100 failed tests

How we count this. Data: UK MOT open data, 2025. Only Class 4 cars on their first MOT of the year are counted. A car that fails and is fixed at the test station still counts as a fail in the first-attempt rate. These are raw results, not adjusted for age, mileage, or peer mix. The MOT does not test engine or gearbox internals.

Note:

These are patterns across 2008 BMW Z4 vehicles in 2025, not a prediction that any one car will have them. Faults are grouped by part of the car. A wear pattern follows age and use more than the way the car was built. They come from MOT defect codes, not manufacturer bulletins, recalls or a diagnosis of any one car.

Body and structure

One fault: fuel cap, 11 times as often as on similar cars.

Figures below are measured across the 516 failed first attempts in 2025 that had a mileage recorded, which allows a like-for-like comparison.

We only list faults with at least 20 failures and a rate of about 2.0 times that of similar cars, which keeps one-off results out of the list.

Fuel cap

Failed on 25 first tests11 times as often as similar carsPossible evidence

What it means

A missing or ineffective fuel filler cap is Major, as is a plain fuel system leak, while a fuel system leaking excessively or a risk of fire has its own, separate wording. A fuel tank with a hole, or a split filler neck, from which fuel can leak must be failed for leaking even if the hole or split is above the fuel line.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Steering

One fault: steering rack, 8.5 times as often as on similar cars.

Steering rack

Failed on 21 first tests8.5 times as often as similar carsPossible evidence

What it means

Steering gear casing retaining devices dangerously loose, or visible relative movement to the chassis or bodywork, is graded Dangerous. A casing not properly attached, or fractured, is Major, but a fracture that affects the stability or attachment of the casing is Dangerous. A gaiter damaged but still keeping dirt out is Minor, and Major once missing or no longer doing so.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Noise, emissions and leaks

One fault: petrol engine warning light, 3.4 times as often as on similar cars.

Petrol engine warning light

Failed on 79 first tests3.4 times as often as similar carsLikely evidence

What it means

The malfunction indicator lamp (MIL) on a petrol engine is a Major failure when it is illuminated indicating a malfunction. The detail line DVSA gives for the same row also names an inoperative lamp. The test covers only certain petrol vehicles, depending on their age, size and fuel type.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Suspension

One fault: shock absorbers (front), 3.1 times as often as on similar cars.

Shock absorbers (front)

Failed on 34 first tests3.1 times as often as similar carsLikely evidence

What it means

Slight seepage that leaves a film of fluid on a shock absorber does not fail it. Severe leakage, or damage so that it does not function, is Major. A shock absorber missing or likely to become detached is graded Dangerous, though a missing one is only rejected if shock absorbers were fitted as standard.

Also noted as an advisory

Testers also noted it as an advisory, worn but not yet failing, on 34 first tests, 2.0 times as often as on similar cars.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage. Advisories count notes recorded on failed first tests only.

Lamps and electrical

One fault: horn, 2.9 times as often as on similar cars.

Horn

Failed on 20 first tests2.9 times as often as similar carsPossible evidence

What it means

A horn that does not work, or is likely to be confused with an emergency vehicle siren, is graded Major. Gongs, bells, sirens and anything with more than one tone, which includes a horn that alternates between its notes, are not allowed, except a gong, bell or siren on vehicles first used before a set date. Sound defects are Minor for named cases such as a bell or harsh sound, and Major under a general row.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Tyres

One wear pattern: tyre tread depth (rear), 2.8 times as often as on similar cars.

Tyre tread depth (rear)

Failed on 31 first tests2.8 times as often as similar carsWear pattern

What it means

Only primary grooves count when tread depth is assessed: those holding the wear indicators, or cut as deep as those when new. Shallower secondary grooves are ignored. Tread depth below the minimum for the vehicle is Dangerous, and so is a pattern not visible over the whole tread, but that second row applies only to vehicles that need the lower minimum.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Seat belts and restraints

One fault: airbag warning light, 2.6 times as often as on similar cars.

Airbag warning light

Failed on 24 first tests2.6 times as often as similar carsPossible evidence

What it means

The airbag warning lamp (SRS MIL in DVSA's wording) is failed only if it indicates a system malfunction, which is Major. A lamp lit to show the passenger airbag is disabled is not to be regarded as a defect. Dashboard messages are not a defect in their own right, though they can help the tester confirm a malfunction.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Advisories

Other things testers noted as worn or close to failing, more often than on similar cars.

An advisory is a note from the tester about something that has not failed yet. It is an early warning, not a fail. Advisories for the faults above are shown with those faults.

Flexible brake hoses (front)

Noted on 39 first tests4.0 times as often as similar carsElevated evidence

Suspension arm ball joint (front)

Noted on 30 first tests2.8 times as often as similar carsElevated evidence

Engine oil leaks (front)

Noted on 21 first tests2.3 times as often as similar carsElevated evidence

Data: UK MOT open data, 2025. Counts cover advisories recorded on failed first tests only, compared with cars of the same age and mileage.

MOT pass rates

How first tests ended, and how the pass rates are counted.

Passed first time
69in every 100
Passed on the first test.
Fixed at the station
5in every 100
Failed, then fixed at the test station the same day.
Failed
26in every 100
Did not pass, and were not fixed at the test station.

First-attempt pass 69.2% of 1,674 first tests (2025): only cars that passed first time count. Official-style pass 74.3%: cars fixed at the test station also count as a pass. The 5 fixed and the 26 not fixed make the 31 in every 100 that did not pass first time.

Same model, other years

Passed first time in every 100, all tested in 2025.

406080100200520082015Older carsNewer cars
4060801002008Older carsNewer cars

Newer cars are younger, so look for a jump rather than the climb. A year earlier (2024), when these cars were a year younger, 70 in every 100 passed first time.

YearPassed first timeFirst tests
200369 in every 1002,277
200469 in every 1002,759
200565 in every 1001,835
200671 in every 1002,767
200773 in every 1002,971
2008 This car69 in every 1001,674
200979 in every 1002,358
201080 in every 1001,890
201181 in every 1001,876
201280 in every 1001,769
201380 in every 1001,515
201482 in every 1001,839
201582 in every 1001,530
201682 in every 1001,179

FAQs

Short answers about how to read this model-year guide.

A 2008 BMW Z4 passed first time about 7 in every 100 less often than the average of the 2007 and 2009 model years. In 2025, 69.2% of 1,674 first MOTs on the 2008 BMW Z4 passed first time (PRS: items fixed at the station the same day, counted as a fail). The official-style rate including PRS is 74.3%. Among 516 failed first-attempt MOT tests (test year 2025), Fuel cap appears more often than on similar cars (4.8% of those tests; 25 observed failures; about 11× more often than similar cars). There is no single reliability score here; this is a pre-purchase checklist built from DVSA open data, not a guarantee for any individual car.
Ranked by how often they were actually recorded, the items that most often failed a 2008 BMW Z4 at the first attempt were Petrol engine warning light (15.3%), each as a share of the year's failed first attempts. That is what goes wrong most often on the car. The common faults table shows a different measure: faults that are unusual compared with similar cars.
Among failed first-attempt tests we highlight patterns that appear more often than on similar cars. Top example: Fuel cap (4.8% of those tests; 25 observed failures; about 11× more often than similar cars). These are statistical signals, not a diagnosis of any individual car.
Fuel cap shows up more often than on similar cars (4.8% of those tests; 25 observed failures; about 11× more often than similar cars). That does not prove a design fault. Age, mileage, and how the car was used still matter. Treat it as a pre-purchase checkpoint, not a manufacturer service bulletin.
Common MOT problem areas for the 2008 BMW Z4 include Fuel cap, Steering rack, Petrol engine warning light. These are the faults that stand out compared with similar cars, not a complete list of what can go wrong on any individual car.
Advisories flag issues noted at the test and are not a fail rate. We show advisory patterns that appear more often than on similar cars among failed first-attempt tests, separate from common failure rows. Use them as early-warning checks, not as a pass/fail score.
This page highlights MOT failure patterns for the 2008 BMW Z4 (registration year) using UK DVSA open data for the selected test year. Patterns are compared with cars of a similar age and mileage. It is a buyer checklist from MOT defect statistics, not a full service history or manufacturer service-bulletin list.
No. MOT tests do not cover engine internals, gearboxes, or many electronic modules. Patterns here come from MOT defect statistics only and should not be read as engine or gearbox reliability scores.

About this data

How this page is built and what it can (and can't) say.

These figures come from UK MOT open data for this model year. We surface common failure patterns against similar cars, not a full reliability score, and not a pass/fail verdict on any individual vehicle.

2024 2025

What we include

UK Class 4 cars only. Normal MOT tests (not retests); first test per vehicle per calendar year; results pass, PRS, or fail.

Same-day repairs

PRS means the car failed items that were fixed at the test station and then passed the same day. We count PRS as a first-attempt fail in headline rates so same-day repairs do not hide problems.

How we compare

We compare this model year with other Class 4 cars of similar age and mileage in the same test year. This model family is left out of the peer group so the car is not measured against itself.

What this does not cover

  • MOTs do not cover engine internals, gearboxes, or many electronics; this is not a full reliability score.
  • Common faults come from MOT defect stats, not manufacturer TSBs or recalls.
  • Age and mileage matching reduces, but does not remove, differences in how cars were used and maintained.
  • If the data for a car is too thin to say anything useful, we say so rather than guess.

Contains public sector information licensed under the Open Government Licence v3.0.

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