MINI Cooper J01 BMW B48 / B38 156 and 204 hp problems
The MINI Cooper J01 used the BMW B48 / B38 from 2024 (Cooper C (1.5, 156 CV) and Cooper S (2.0, 204 CV)). 3 documented faults affect it; the most important is “deterioration of hoses and seals in the cooling circuit, with coolant loss” (medium severity, occasional). Our verdict: “Buy”. Among the documented engines of the MINI Cooper J01, the safest option is the BMW B38 / B37.
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Engine score on this car
7.6 out of 10Good reliability
Only counting the faults that affect the versions and years of the Cooper J01. How we calculate it
Overall score for the MINI Cooper J01
6.6 out of 10Acceptable reliability
Engines, gearbox, suspension, brakes, electronics and the rest of the car. See breakdown
BMW B48 (B48A20 / B48B20) / B38 (B38A15 / B38B15) · Petrol
- In the Cooper J01
- since 2024[1]
- Names
- Cooper C (1.5, 156 CV) · Cooper S (2.0, 204 CV)
- Faults that affect it
- 3
Verdict for the versions it uses
B38 1.5 136 hp (MINI Cooper, 118i)since 2014 · 136 hp · B38A15, B38B15
BuyWe have found no serious, widespread fault documented specifically for the B38; it shares with the rest of the family the same watch points around the cooling circuit and the oil seals.[2]
B48 2.0 178-197 hp (120i, 220i, 320i, 520i, X1/X2/X3 20i, MINI Cooper S)since 2014 · 178–197 hp · B48A20, B48B20
BuyIt is the most widely fitted B48 version and has no serious, widespread fault on record; it is worth checking the cooling circuit and any oil leaks next to the turbo and the VANOS.[2]
Faults that affect the Cooper J01
Only those that affect the versions and years that this car used. The BMW B48 / B38 has 4 documented faults in total.
- Medium severityFrequency: OccasionalCoolingDeterioration of hoses and seals in the cooling circuit, with coolant lossYes: over the years and many heat cycles, the hoses, the expansion tank and some of the plastic seals in the B48/B38 cooling circuit can deteriorate and lose coolant, sometimes without any visible puddle under the car.
- Medium severityFrequency: OccasionalLubricationOil leaks or seepage from seals and covers, near the turbo and the VANOSYes: over time, oil seepage or leaks can appear at seals, covers and crankcase ventilation connections, in an area of the engine close to the turbo and the VANOS system.
- Low severityFrequency: CommonIntakeCarbon build-up on the intake valves (direct injection)Yes, as on most direct-injection engines: because they are not washed by fuel, the intake valves on the B48/B38 build up carbon over the years, especially in urban use, with a loss of smoothness and a less stable idle.
What to check before buying a used MINI Cooper J01 BMW B48 / B38 156 and 204 hp
Each point comes from a documented fault that affects this car. You can tick them off as you inspect it.
If it has the BMW B48 / B38 (since 2024)
Other engines and gearboxes of the MINI Cooper J01
Score for each one with the faults that affect this car, from best to worst.
Faults of the MINI Cooper J01 outside the engine
Suspension, brakes, electronics and the rest of the car: they occur with any engine.
- Critical severityFrequency: OccasionalElectrical systemHigh-voltage battery cell modules out of specification (electric Cooper, risk of short circuit and fire)MINI has recalled electric Cooper (and Aceman) models because the high-voltage battery cell modules may not meet specification and could cause a short circuit, with a possible fire even with the car parked. The campaign started in January 2025 and was extended during 2025 to batches built between April 2023 and November 2024.
- Critical severityFrequency: OccasionalBrakesBrake booster with a hollow shaft badly welded (2025 campaign)In January 2025 MINI recalled Coopers, Countryman and Aceman models built between 12 December 2023 and 26 August 2024 because the weld on the hollow shaft of the brake servomotor can break under high braking pressures. The pedal requires more force, braking distance increases, and the ABS and DSC lose assistance.
- Critical severityFrequency: OccasionalAirbags and safetySeatbelts badly manufactured with reduced restraint (2025 cars)In October 2025 MINI recalled 6,331 Coopers and Countryman models built between 18 June and 25 August 2025 because the seatbelts were not manufactured correctly. In a collision, their restraining function may be reduced and the risk of injury increased.
Buying a MINI Cooper J01 BMW B48 / B38 156 and 204 hp?
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The MINI Cooper J01 has 3 documented recalls and campaigns. See which ones and how to find out if they affect you
Frequently asked questions
Is the MINI Cooper J01 BMW B48 / B38 156 and 204 hp reliable?
The MINI Cooper J01 used the BMW B48 / B38 from 2024 (Cooper C (1.5, 156 CV) and Cooper S (2.0, 204 CV)). 3 documented faults affect it; the most important is “deterioration of hoses and seals in the cooling circuit, with coolant loss” (medium severity, occasional). Our verdict: “Buy”. Among the documented engines of the MINI Cooper J01, the safest option is the BMW B38 / B37.
What faults does the MINI Cooper J01 BMW B48 / B38 156 and 204 hp have?
The documented ones that affect this car are: deterioration of hoses and seals in the cooling circuit, with coolant loss (medium severity), oil leaks or seepage from seals and covers, near the turbo and the VANOS (medium severity) and carbon build-up on the intake valves (direct injection) (low severity).
Which engine should you choose for the MINI Cooper J01?
The safest option is the BMW B38 / B37, with a «Buy» verdict.
Own a MINI Cooper J01 BMW B48 / B38 156 and 204 hp? Tell us what faults you have had and at how many kilometres. Report your fault.
Sources
Every fact on this page links to its source. If you find an error, let us know.
- Mini Cooper (J01)Wikipedia (inglés) · Other source · consulted 31 October 2026
- Motor BMW B48: defectos, mantenimiento y guía de compraRecambios y Accesorios BMW (blog) · Technical documentation · consulted 27 September 2026 · in Spanish