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B38K15T0

B38K15T0 231 hp (BMW i8) engine: faults and reliability

BMW B38 (1.5 gasolina) and B37 (1.5 diésel) de tres cilindros version

With caution

We have found no failure data for the i8's petrol engine; around 20,465 units were built and, as a niche hybrid, there is little public information, so check its history with an official service centre.[1]

Years
2014–2020
Power
231 hp
Faults that affect it
2
0 of high or critical severity
Cars that use it
1
in our database

2 sourcesHow we work

What changes in this version

High-performance version of the 1.5: 170 kW (231 hp) and 320 Nm, working alongside an electric motor in the BMW i8 plug-in hybrid (coupé 2014-2020, roadster 2018-2020).[1][2]

Engine codes of this version: B38K15T0.

Faults of the B38K15T0 engine

The documented engine faults that affect this version and its years, from most to least important.

  1. 1Medium severityFrequency: RareCoolingCoolant leaks and water pump or thermostat failure on the B38Two sources point to the cooling circuit (thermostat housing, electric water pump and hoses) as the most cited wear point on the B38, with leaks from around 70,000 km. The data is scarce and of uneven quality, so it is treated as a risk to watch rather than a widespread fault.
  2. 2Low severityFrequency: OccasionalIntakeCarbon build-up on the B38's intake valves and injectorsAs a direct-injection engine, the B38 builds up carbon deposits on the intake valves and injectors, like other direct-injection petrol engines. The German press cites it as the point to watch in an otherwise trouble-free engine, and it is noticed mainly on short journeys.

Cars fitted with the B38K15T0 engine

Open each car to see all its faults with this engine and what to check before buying it.

BMW

Frequently asked questions

Is the B38K15T0 engine reliable?

Our verdict is “With caution”. We have found no failure data for the i8's petrol engine; around 20,465 units were built and, as a niche hybrid, there is little public information, so check its history with an official service centre.[1]

What faults does the B38K15T0 engine have?

The documented ones that affect this version, by importance: coolant leaks and water pump or thermostat failure on the B38 (medium severity) and carbon build-up on the B38's intake valves and injectors (low severity).

Which cars use the B38K15T0 engine?

BMW i8 I12 (2014–2020).[1][2]

Are you buying a car with the B38K15T0 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.

  1. BMW i8 (Wikipedia)Wikipedia · Other source · consulted 4 October 2026
  2. BMW B38 (Wikipedia)Wikipedia · Other source · consulted 4 October 2026