Reconditioned BMW X3 Engine

BMW X3: 6 engine codes for an SUV whose use puts the engine under serious strain

The BMW X3 is an xDrive all-wheel-drive SUV used for heavy urban driving as well as long motorway journeys under load, and even towing. This driving profile — frequent low-speed running, an engine that rarely reaches its optimal temperature in town, and high motorway loads — accelerates wear on the piston rings, bearings and timing systems. When the engine reaches the end of its life, accurate identification of the unit is critical: the X3 covered here spans 4 distinct engine variants, petrol and diesel, each paired with its own engine code.

Diesel: three codes covering two 3.0 displacements and one 2.0

On the diesel side, the 3.0 d carries the code N57D30B, while the 3.0d xDrive30d is paired with the code N57D30A. Both codes refer to variants of the 6-cylinder in-line N57 family, but they are not interchangeable: the final letter distinguishes different power outputs and mechanical configurations. The 2.0d is based on the code N47D20C, a 4-cylinder diesel known for significant strain on its timing chain — a point to check before any decision is made to replace the unit.

Petrol 2.0i: three N20 variants not to be confused

The 2.0i engine is the most represented in the range, with three distinct codes: N20B20A, N20B20B and N20B20D. These three codes correspond to internal evolutions of the same 2.0-litre turbocharged 4-cylinder petrol engine. The final letter of the code changes the actual mechanical specifications; fitting an N20B20A in place of an N20B20D is a common identification error. The code stamped on the engine block is the only reliable reference when ordering the correct replacement. All engines listed here are bare engines.