Used Mazda 3 Crankshaft

Every Mazda 3 variant has a crankshaft — it is a fundamental internal engine component present in all petrol and diesel engines across every generation of the car, from the first-generation BK (2003–2009) through the second-generation BL (2009–2013), third-generation BM (2013–2019), and fourth-generation BP (2019–present). What varies is the exact crankshaft specification, which is determined primarily by the engine code rather than the generation badge. Always supply your engine code — found on your V5C or via a VIN check — when requesting a quote from a breaker.

These sit in different generations — the 2007 car is first-generation BK and the 2011 car is second-generation BL — so the crankshafts are unlikely to be interchangeable even if the engine displacement sounds similar. The critical factor is the engine code: if both cars share the exact same engine code, fitment becomes more plausible, but you should still confirm this directly with the breaker against your registration before purchasing. Do not assume a match based on year or body style alone.

Trim level has no bearing on crankshaft fitment whatsoever — SE, Sport, GT Sport, and any other Mazda 3 trim designation are cosmetic and equipment distinctions, not mechanical ones. What determines the correct crankshaft is the engine code, fuel type (petrol or diesel), and the specific engine variant fitted to your car. Give the breaker your engine code rather than your trim name and they will be able to match the part accurately.

Both years fall within the third-generation BM (2013–2019), so there is a reasonable chance of compatibility if the engine codes match, but Mazda did make running production changes during this generation and the crankshaft specification can vary by engine code even within the same generation. Share your full engine code with the breaker so they can verify the part matches your specific engine build rather than relying on the year alone. Never assume a within-generation match without that check.

Yes, fuel type matters significantly — petrol and diesel engines have different internal architecture, compression ratios, and crankshaft designs, so they use entirely different crankshafts that are not interchangeable. Even within petrol or diesel, different engine codes (for example a 2.0 petrol versus a 1.5 petrol in the BM generation) will use different crankshafts. Always specify both your fuel type and engine code when contacting a breaker to avoid being quoted an incompatible part.

Body style makes absolutely no difference to crankshaft fitment — the engine in the hatchback and the saloon Fastback is mechanically the same unit where the engine code matches. The crankshaft is deep inside the engine block and is entirely unaffected by how the bodywork above it is arranged. Match by engine code and fuel type, not by body style, and confirm with the breaker against your registration.