Model Reports 4 min read Updated 18 Oct 2026

BMW 6 Series 2004: reliability & common MOT faults

In 2025, 70 in every 100 first MOTs on a 2004 BMW 6 Series were passes.

Summary

With 917 first tests, there are too few to say whether the 2004 BMW 6 Series differs from the model years either side. Treat the faults below as a checklist.

At a glance

How 917 first tests went in 2025.

Passed first time
70 in every 100
Did not pass first time
30 in every 100271 failed first-attempt tests
The typical car
21 yearsabout 106,911 miles
First tests counted
917

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 2004 BMW 6 Series vehicles in 2025, not a prediction that any one car will have them. Faults are grouped by part of the car. They come from MOT defect codes, not manufacturer bulletins, recalls or a diagnosis of any one car.

Suspension

Two faults. The strongest is the suspension arm pins and bushes (rear): 10 times as often as on similar cars.

Figures below are measured across the 271 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.

Suspension arm pins and bushes (rear)

Failed on 20 first tests10 times as often as similar carsPossible evidence

What it means

Pins and bushes on suspension arms fail as Major when they are excessively worn. They are graded Dangerous when likely to become detached. DVSA uses the same wording for a suspension joint.

Also noted as an advisory

Testers also noted it as an advisory, worn but not yet failing, on 45 first tests, 8.2 times as often as on similar cars.

Coil spring (rear)

Failed on 24 first tests3.4 times as often as similar carsPossible evidence

What it means

A missing bump stop rubber is not a reason to fail a coil spring. When the vehicle is jacked and lowered, a spring that does not correctly locate as the suspension returns to its normal running position is rejected as insecurely attached. A missing spring is Major, and graded Dangerous where directional control is affected.

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

Seat belts and restraints

One fault: airbag warning light, 3.5 times as often as on similar cars.

Airbag warning light

Failed on 31 first tests3.5 times as often as similar carsLikely 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.

Engine oil leaks

Noted on 97 first tests2.2 times as often as similar carsElevated evidence

Rigid brake pipes (front)

Noted on 42 first tests2.1 times as often as similar carsElevated evidence

Tyre tread depth (rear)

Noted on 48 first tests2.1 times as often as similar carsWear pattern

Brake discs (rear)

Noted on 35 first tests2.0 times as often as similar carsWear pattern

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
70in 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
25in every 100
Did not pass, and were not fixed at the test station.

First-attempt pass 70.4% of 917 first tests (2025): only cars that passed first time count. Official-style pass 74.6%: cars fixed at the test station also count as a pass. The 5 fixed and the 25 not fixed make the 30 in every 100 that did not pass first time.

Same model, other years

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

406080100200420102015Newer cars
40608010020042010Newer 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, 72 in every 100 passed first time.

YearPassed first timeFirst tests
2004 This car70 in every 100917
200569 in every 1001,113
200670 in every 1001,283
200774 in every 1001,081
200876 in every 100980
200975 in every 100530
201080 in every 100493
201177 in every 100583
201278 in every 1001,360
201379 in every 1001,784
201478 in every 1001,816
201582 in every 1001,820
201685 in every 1001,726
201784 in every 1001,254
201886 in every 1002,168
201988 in every 100990

FAQs

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

With 917 first tests, there are too few to say whether the 2004 BMW 6 Series differs from the model years either side. Treat the faults below as a checklist. In 2025, 70.4% of 917 first MOTs on the 2004 BMW 6 Series passed first time (PRS: items fixed at the station the same day, counted as a fail). The official-style rate including PRS is 74.6%. Among 271 failed first-attempt MOT tests (test year 2025), Suspension arm pins and bushes (rear) appears more often than on similar cars (7.4% of those tests; 20 observed failures; about 10× 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.
Among failed first-attempt tests we highlight patterns that appear more often than on similar cars. Top example: Suspension arm pins and bushes (rear) (7.4% of those tests; 20 observed failures; about 10× more often than similar cars). These are statistical signals, not a diagnosis of any individual car.
Suspension arm pins and bushes (rear) shows up more often than on similar cars (7.4% of those tests; 20 observed failures; about 10× 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 2004 BMW 6 Series include Suspension arm pins and bushes (rear), Airbag warning light, Coil spring (rear). 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 2004 BMW 6 Series (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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