Reconditioned BMW 2 Series Engine

5 petrol engine codes for the 2 Series (2014–2021): N20, B48 or B38?

The petrol BMW 2 Series spans two engine capacities and three distinct engine families. The 2.0i accounts for the bulk of the range, with four different codes — N20B20A, N20B20B, N20B20D (the older N20 architecture, with the timing chain at the rear of the block) and B48A20A (the new B-platform, introduced progressively from 2015 onwards) — whilst the 1.5i uses a single code, the B38A15A, a modular three-cylinder from the same B family. These two families share no internal parts: confusing an N20 with a B48 when placing an order is the most common mistake made on this model.

N20 and B48: two generations of 2.0i with very different profiles

The N20B20 (available as A, B and D variants depending on power output and market) is well known for timing chain issues on the gearbox side of the block: wear to the tensioner and plastic guide rail on early units. The B48A20A, which replaced it, addresses this structural weakness with a revised architecture and repositioned timing system. On a 2014–2015 2 Series, the 2.0i typically comes with an N20; from 2016–2017 onwards, the switch to the B48 was made depending on the trim level and market. The identification plate under the bonnet — not the model year alone — remains the only reliable way to confirm which family is fitted.

The B38A15A: the three-cylinder in the 1.5i, a different proposition

The B38A15A shares the modular platform of the B48 but is not a functionally interchangeable scaled-down version of it. This engine is fitted primarily to entry-level versions of the 2 Series Active Tourer and Gran Tourer. Its per-cylinder capacity is identical to that of the B48, which reflects BMW's modular design philosophy, but its thermal management and mountings differ. All engines offered here are bare engines: ancillaries, turbo, alternator and starter motor are not included and must be reused or ordered separately.