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BMW 4 Series exhaust, emissions and leaks problems

DVSA MOT tests 2022–2025 · 70,637 MOT tests · Updated

At 7 years, 0.5 in 100 MOT tests of the BMW 4 Series failed on exhaust, emissions and leaks, against 1.7 for all class 4 vehicles the same age (all test years; 70,637 MOT tests) [1].

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  • Against all class 4 vehicles the same age: fails less often than all class 4 vehicles the same age (0.3× (0.27–0.33×)) (all test years), 356 MOT tests with a fail
  • By age: seen at 10 ages from 3 to 12 years, 417,430 MOT tests
  • MOT tests at 7 years: 70,637 for the BMW 4 Series

Figures are for the model as a whole, not for one car.

What the MOT tests show

What we know

0.5 fails per 100 MOT tests at 7 years, against 1.7 for all class 4 vehicles tested at 7 (all test years). The BMW 4 Series fails less often here.

Why it matters

An exhaust, emissions and leaks fail stops the car passing until it is fixed.

What to check

Start the car from cold and look for smoke at the exhaust, listen for blowing joints, and look under the engine and gearbox for fresh oil or fluid drips.

BMW 4 Series exhaust, emissions and leaks fails by age

BMW 4 Series exhaust, emissions and leaks fails per 100 MOT tests by ageSolid line: the BMW 4 Series. Dashed line: all cars the same age. The table below lists every value.0243 years: 0.2 per 100 (all cars 0.5), 30,556 MOT tests34 years: 0.3 per 100 (all cars 0.7), 38,917 MOT tests45 years: 0.4 per 100 (all cars 1.0), 48,863 MOT tests56 years: 0.4 per 100 (all cars 1.3), 62,517 MOT tests67 years: 0.5 per 100 (all cars 1.7), 70,637 MOT tests78 years: 0.5 per 100 (all cars 2.1), 67,165 MOT tests89 years: 0.7 per 100 (all cars 2.4), 51,085 MOT tests910 years: 0.9 per 100 (all cars 2.8), 32,238 MOT tests1011 years: 1.3 per 100 (all cars 3.2), 13,926 MOT tests1112 years: 1.2 per 100 (all cars 3.7), 1,526 MOT tests12
Fails per 100 MOT tests by age, all first-use years pooled. BMW 4 Series All class 4 vehicles the same age
AgeMOT testsFails per 100All class 4 vehicles the same age
330,5560.20.5
438,9170.30.7
548,8630.41.0
662,5170.41.3
770,6370.51.7
867,1650.52.1
951,0850.72.4
1032,2380.92.8
1113,9261.33.2
121,5261.23.7

All first-use years of the BMW 4 Series pooled at each age, against all class 4 vehicles at that age over all 2022–2025 test years.

What fails in the exhaust, emissions and leaks at 7 years

Advisories (not fails)

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By engine and fuel

  • 2.0 diesel: 0.5 per 100 at 7 years, fails less often than diesel class 4 vehicles the same age (0.2–0.3×) (all test years; 32,454 MOT tests)
  • 2.0 petrol: 0.7 per 100 at 7 years, about average for petrol class 4 vehicles the same age (all test years; 16,300 MOT tests)
  • 3.0 diesel: 0.2 per 100 at 7 years, about average for diesel class 4 vehicles the same age (all test years; 16,523 MOT tests)

How to check on a test drive

Start the car from cold and look for smoke at the exhaust, listen for blowing joints, and look under the engine and gearbox for fresh oil or fluid drips.

The most common advisory here in MOT records: Transmission oil leaks: leak, but not excessive.

Check one BMW 4 Series, not the average

The figures here describe BMW 4 Series cars as a group. These free tools answer for one car. Each line says what the tool reads.

Other BMW 4 Series problems

Exhaust, emissions and leaks on rival models

Questions people ask

Does the BMW 4 Series have more exhaust, emissions and leaks problems than other cars?

0.27 to 0.33 times the exhaust, emissions and leaks fail rate of all class 4 vehicles the same age at 7 years (all test years), from 70,637 MOT tests. The interval is clear of 0.8 in the same direction at 8 of the 10 ages seen (ages up to 18 with at least 100 MOT tests with a fail).

How common are BMW 4 Series exhaust, emissions and leaks problems?

0.5 in 100 MOT tests at 7 years failed on exhaust, emissions and leaks, against 1.7 for all class 4 vehicles the same age (all test years; 70,637 MOT tests).

Sources

  1. Driver and Vehicle Standards Agency, Anonymised MOT tests and results, 2022 to 2025. DVSA MOT data, Open Government Licence v3.0, 417,430 MOT tests. Accessed 7 Oct 2026.

Parts: against all class 4 vehicles at the same age, all 2022–2025 test years pooled, not adjusted for mileage. Breakdowns and non-MOT faults are not in this data. How we compare