Model Reports 4 min read Updated 18 Oct 2026

BMW 1 Series 2004: reliability & common MOT faults

In 2025, 61 in every 100 first MOTs on a 2004 BMW 1 Series were passes. Most common reason for a fail: Airbag warning light.

Summary

The 2004 BMW 1 Series follows the pattern of the model years either side.

At a glance

How 1,046 first tests went in 2025.

Passed first time
61 in every 100
Did not pass first time
39 in every 100411 failed first-attempt tests
The typical car
21 yearsabout 118,802 miles
First tests counted
1,046

What failed most often

  1. Airbag warning light14 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 2004 BMW 1 Series 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.

Brakes

Two faults. The strongest is the flexible brake hoses (rear): 6.1 times as often as on similar cars.

Figures below are measured across the 410 of 411 failed first attempts (99.8%) that recorded an odometer reading in 2025. Mileage is needed to compare like with like.

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.

Flexible brake hoses (rear)

Failed on 27 first tests6.1 times as often as similar carsPossible evidence

What it means

Testers reject a flexible brake hose for being excessively damaged or chafed only if it is severe enough to expose the reinforcement. Slight damage, chafing or twisting is graded Minor. A leak is graded Dangerous on a hydraulic braking system and Major on an air system, and a hose damaged and likely to fail is also Dangerous.

Also noted as an advisory

Testers also noted it as an advisory, worn but not yet failing, on 37 first tests, 2.8 times as often as on similar cars.

Flexible brake hoses (front)

Failed on 27 first tests3.5 times as often as similar carsPossible evidence

What it means

Testers reject a flexible brake hose for being excessively damaged or chafed only if it is severe enough to expose the reinforcement. Slight damage, chafing or twisting is graded Minor. A leak is graded Dangerous on a hydraulic braking system and Major on an air system, and a hose damaged and likely to fail is also Dangerous.

Also noted as an advisory

Testers also noted it as an advisory, worn but not yet failing, on 69 first tests, 6.0 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.

Seat belts and restraints

One fault: airbag warning light, 3.9 times as often as on similar cars.

Airbag warning light

Failed on 57 first tests3.9 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.

Lamps and electrical

One fault: individual direction indicators (rear), 3.8 times as often as on similar cars.

Individual direction indicators (rear)

Failed on 27 first tests3.8 times as often as similar carsPossible evidence

What it means

Direction indicators must be amber, though vehicles first used before a set date may have white at the front and red at the rear when the indicators are combined with stop or position lamps, and sequential or dynamic ones are not a reason to fail. A lamp that is missing, inoperative or has more than half of a multiple light source not functioning is graded Major. A flashing rate outside the permitted range is graded Minor.

Also noted as an advisory

Testers also noted it as an advisory, worn but not yet failing, on 22 first tests, 4.6 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.

Suspension

Two faults. The strongest is the shock absorbers (front): 3.3 times as often as on similar cars.

Shock absorbers (front)

Failed on 27 first tests3.3 times as often as similar carsPossible 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 30 first tests, 2.0 times as often as on similar cars.

Shock absorbers (rear)

Failed on 23 first tests2.2 times as often as similar carsPossible 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.

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

Tyres

One wear pattern: tyre tread depth (rear), 2.6 times as often as on similar cars.

Tyre tread depth (rear)

Failed on 27 first tests2.6 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.

Visibility

One fault: windscreen washers (front), 2.1 times as often as on similar cars.

Windscreen washers (front)

Failed on 24 first tests2.1 times as often as similar carsPossible evidence

What it means

Windscreen washers that are not working, or do not provide sufficient fluid to clear the windscreen, are graded Major. They must provide enough fluid for the wipers to clear the windscreen effectively. Vehicles with an opening windscreen, or some other adequate view to the front, left and right, are not inspected for washers.

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.

Individual direction indicators (front)

Noted on 22 first tests4.4 times as often as similar carsElevated evidence

Suspension arm pins and bushes (rear)

Noted on 33 first tests3.4 times as often as similar carsElevated evidence

Suspension sub-frame (rear)

Noted on 62 first tests2.5 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
61in every 100
Passed on the first test.
Fixed at the station
8in every 100
Failed, then fixed at the test station the same day.
Failed
31in every 100
Did not pass, and were not fixed at the test station.

First-attempt pass 60.7% of 1,046 first tests (2025): only cars that passed first time count. Official-style pass 68.9%: cars fixed at the test station also count as a pass. The 8 fixed and the 31 not fixed make the 39 in every 100 that did not pass first time.

Petrol and diesel

First testsPassed first time, as tested
Petrol52963
Diesel51658

Figures are in every 100 first tests.

Same model, other years

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

4060801002004201020152020Newer cars
406080100200420102020Newer cars

Newer cars are younger, so look for a jump rather than the climb.

YearPassed first timeFirst tests
2004 This car61 in every 1001,046
200561 in every 1004,265
200662 in every 1006,355
200764 in every 1007,653
200865 in every 10012,308
200965 in every 10016,332
201066 in every 10019,698
201167 in every 10019,761
201266 in every 10026,485
201370 in every 10033,958
201473 in every 10028,931
201578 in every 10030,142
201679 in every 10030,546
201782 in every 10031,626
201883 in every 10025,832
201985 in every 10026,813
202088 in every 10023,203
202190 in every 10017,952
202291 in every 10013,102

FAQs

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

The 2004 BMW 1 Series follows the pattern of the model years either side. Its main cause of failure was Airbag warning light, about 14 in every 100 failed tests. In 2025, 60.7% of 1,046 first MOTs on the 2004 BMW 1 Series passed first time (PRS: items fixed at the station the same day, counted as a fail). The official-style rate including PRS is 68.9%. Among 411 failed first-attempt MOT tests (test year 2025), Flexible brake hoses (rear) appears more often than on similar cars (6.6% of those tests; 27 observed failures; about 6.1× 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 2004 BMW 1 Series at the first attempt were Airbag warning light (13.9%), 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: Flexible brake hoses (rear) (6.6% of those tests; 27 observed failures; about 6.1× more often than similar cars). These are statistical signals, not a diagnosis of any individual car.
Flexible brake hoses (rear) shows up more often than on similar cars (6.6% of those tests; 27 observed failures; about 6.1× 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 1 Series include Flexible brake hoses (rear), Airbag warning light, Individual direction indicators (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 1 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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