B38A15B38B15
B38 1.5 136 hp (MINI Cooper, 118i) engine: faults and reliability
BMW B48 (B48A20 / B48B20) / B38 (B38A15 / B38B15) version
Buy
We 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.[1]
What changes in this version
Faults of the B38A15 engine
The documented engine faults that affect this version and its years, from most to least important.
- 1Medium 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.
- 2Medium 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.
- 3High severityFrequency: RareTimingTiming chain on the early units (2014-2018), redesigned in the B48TUWe have found no documented cases of timing chain breakage on the B48. The one concrete fact that does exist is that BMW redesigned the chain as a single piece in the 2018 B48TU update, which points to an area for improvement in engines built before that date.
- 4Low 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.
Cars fitted with the B38A15 engine
Open each car to see all its faults with this engine and what to check before buying it.
BMW
- BMW Serie 1 F20118i · 120i · 125i2015–2019[2][5][6]
- BMW Serie 1 F40118i · 120isince 2019[2][5]
MINI
- MINI Cooper F56Cooper · Cooper S · John Cooper Works2014–2024[2][3][4]
- MINI Countryman F60Cooper · Cooper S · John Cooper Works2017–2023[2][4]
- MINI Cooper F55Cooper · Cooper S2014–2024[3]
Frequently asked questions
Is the B38A15 engine reliable?
Our verdict is “Buy”. We 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.[1]
What faults does the B38A15 engine have?
The documented ones that affect this version, by importance: 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), timing chain on the early units (2014-2018), redesigned in the B48TU (high severity) and carbon build-up on the intake valves (direct injection) (low severity).
Are you buying a car with the B38A15 engine?
We will put you in touch with a partner only if you authorise it in the form.
Do you have a car with this engine? Tell us which 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.
- Motor BMW B48: defectos, mantenimiento y guía de compraRecambios y Accesorios BMW (blog) · Technical documentation · consulted 27 September 2026 · in Spanish
- BMW B38Wikipedia (inglés) · Other source · consulted 27 September 2026
- Mini HatchWikipedia (inglés) · Other source · consulted 27 September 2026
- MINI (BMW)Wikipedia (español) · Other source · consulted 27 September 2026 · in Spanish
- BMW B48Wikipedia (inglés) · Other source · consulted 27 September 2026
- BMW 1 Series (F20)Wikipedia · Other source · consulted 29 October 2026