When you send an F30 ad in my live broadcasts, I usually recommend the 320d due to the chronic issues found in all gasoline engines below 2L in the 3 Series, particularly the recent 190 PS or previous 184 PS models; the 177 PS from the E90 and earlier should be avoided. However, if you're considering a newer and lower-class BMW/Mini, especially a facelifted F20 and if you've decided on diesel, you’ll encounter another problem.

The BMW B37 1.5L 3-cylinder diesel engine was introduced in 2014 as part of BMW's modular engine family, designed for high efficiency. Commonly used in both BMW and Mini models, with power ranging between 95 and 116 PS, this engine stands out on paper for its compact structure and suitability for city driving.

BMW and Mini Models it was used in:

1. BMW 1 Series (F20/F21):

 - Models: 114d, 116d (2014–2019)

2. BMW 2 Series Active Tourer (F45/F46):

 - Models: 214d, 216d (2014–present)

3. BMW X1 (F48):

 - Model: sDrive16d (2015–present)

4. BMW 2 Series Gran Tourer:

 - Model: 216d (2015–present)

5. Mini Hatchback (F56):

 - Models: Mini One D, Mini Cooper D (2014–present)

6. Mini Clubman (F54):

 - Models: One D, Cooper D (2015–present)

7. Mini Countryman (F60):

 - Models: One D, Cooper D (2016–present)

Common Problems:

1. Fuel Sensor Failure: When the fuel sensor is strained, it bursts and leaks fuel into the socket, which eventually fills the ECU with fuel, leading to an environment pressure sensor error. It also necessitates changing the DPF sensor and glow plugs, as well as cleaning the DPF. BMW is aware of this fault and has recalled all affected vehicles. The EGR cooler is also replaced free of charge while fixing the issue.

2. EGR (Exhaust Gas Recirculation) System: Like many diesel engines, the EGR valve can clog over time, leading to performance loss and faults. Regular cleaning is recommended after 150,000 km, and the valve may need to be replaced.

3. Timing Chain Wear: The timing chain can become noisy around 180,000–200,000 km. At this point, it should be replaced, as a fully snapped chain can severely damage the engine.

4. DPF (Diesel Particulate Filter) Clogging: After 200,000 km, the DPF can clog, causing power loss. Cleaning might provide a temporary solution, but eventually, the filter needs replacing, and high-quality fuel should be used.

5. Vibration Issues: Early versions of the engine exhibited excessive vibration at idle. Updates made in 2017 resolved this issue with the use of balance shafts.

6. Turbo and Intake System Issues: Dirt build-up in the turbo and intake manifold is common and can negatively impact performance. Regular air filter changes and cleaning the intake system can reduce these problems.

Is It Worth Buying?

Abroad, the B37 is generally seen as a fuel-efficient option for city driving. However, here, it's hard to call any vehicle with this engine 'economical.' Notice how engine sizes are decreasing over time, regardless of the brand or segment, while chronic problems are increasing; it's as if internal combustion engine manufacturers are colluding to accelerate the EV transition.

Anyway, let's not stray from the point. As with almost every BMW, for this engine to last long, it's important to avoid aggressive driving, use the right quality oil, change oil frequently, and maintain regular servicing.

Sources:

https://mymotorlist.com/engines/bmw/b37d15/

https://motoranimal.com/mini-1-5-diesel-engine-problems-durability/

https://www.tiktok.com/@bmwminiatasehir/video/7290550027045342470?_r=1&_t=8pfXMY7AlpH&link_tag=2