Second Hand BMW 4 Series Crankshaft

The BMW 4 Series F32/F33/F36 generation ran from 2013 to 2020, with a facelift in 2017, so both years sit within the same generation — but whether the crankshaft crosses the facelift boundary depends entirely on the engine code, not the model year alone. Two cars can share the same badge year but use different engine variants, and a crankshaft is machined to very precise tolerances for a specific engine family. Supply your engine code (found on your V5 or via a VIN check) to the breaker, who can confirm whether the donor unit is a genuine match.

This is a realistic question because the F30 3 Series and F32/F36 4 Series share several engine families, and in some cases the crankshaft is the same casting — but fitment is determined by engine code, not by which model it came out of. If your 4 Series and the donor 3 Series carry an identical engine code (for example both being N20B20 or B47D20), the internal components may well be shared, but you must confirm this with the breaker against your exact registration before purchasing.

For standard 4 Series variants, trim level — whether Sport, M Sport, or Luxury — has no bearing on crankshaft fitment whatsoever, as the engine code is what defines the crankshaft specification. The M4, however, is a different matter: it uses a separate high-performance engine (the S55B30 in the F82 generation), so its crankshaft is not interchangeable with a standard 4 Series unit. Always confirm fitment with the breaker using your engine code rather than your trim badge.

The crankshaft itself is an internal engine component and is not directly affected by gearbox type — a 420d with the B47D20 engine should use the same crankshaft regardless of whether it has a manual or automatic gearbox. What can vary is the rear flange specification relating to the flywheel or flexplate, so it is worth mentioning your gearbox type to the breaker when sourcing the part, just to be safe. Confirm the full engine code with the breaker before agreeing to buy.

No — body style makes no difference to crankshaft fitment, as the crankshaft is internal to the engine block and is identical across coupe (F32), convertible (F33), and Gran Coupe (F36) variants that share the same engine code. The part you need is determined solely by the engine fitted, so a crankshaft from a Gran Coupe with the same engine code as your convertible is just as suitable as one from an identical coupe. Provide your engine code to the breaker to get an accurate match.

Yes — every BMW 4 Series, across all variants and engine options, has a crankshaft; it is a fundamental rotating component inside every internal combustion engine, converting the up-and-down motion of the pistons into the rotation that ultimately drives the wheels. Whether your 4 Series is petrol or diesel, turbocharged or not, the crankshaft is present in all of them. What differs between variants is the exact specification of the crankshaft, which is why your engine code is the critical detail to give a breaker when sourcing a used unit.