Second Hand BMW Z4 Timing Chain

All BMW Z4 engines across every generation use a timing chain rather than a timing belt, so there is no cambelt replacement interval to worry about. The chain is designed to last the life of the engine, though wear, stretch, and guide failure are known issues on higher-mileage units. If you're sourcing a used timing chain assembly from a breaker, this is a genuine like-for-like replacement part for your Z4.

Almost certainly not — the E85 and G29 generations use completely different engine families, so the timing chain assemblies, tensioners, and guides are specific to each engine code. The E85 used engines such as the M54, N46, N52, and M54B, while the G29 uses the B46 and B58 family, which are entirely different in architecture. Always confirm the exact engine code from your V5 or a VIN check and supply it to the breaker before agreeing any sale.

Yes — the engine code is the single most important detail for this part, because BMW fitted several different engines to the Z4 across overlapping years and the timing chain assembly is specific to the engine, not the model year. Two Z4s from the same year could have different engines and completely incompatible timing chains. Find your engine code on your V5 logbook or via a VIN check and give it to the breaker before anything else.

Trim level itself makes no difference to timing chain fitment, but the engine code does — and different trim levels often correspond to different engines. The sDrive20i uses the B48 four-cylinder engine, while the M40i uses the B58 six-cylinder, and these have different timing chain configurations. Ignore the trim badge and focus on the engine code; a B58 chain from any donor vehicle with a B58 is what matters, regardless of what trim that donor car was.

If the engine codes genuinely match, fitment is likely, but the E89 did see running production changes across its life and ancillary components such as tensioners and guides can vary mid-production. Name the engine code clearly when speaking to the breaker and ask them to confirm the chain and associated hardware against your specific registration, as subtle specification changes can catch buyers out.

BMW used many of its engines across multiple model lines, so if the engine code is a genuine match — for example a B58 from a 340i in a G29 Z4 — the core timing chain components are often shared. However, you should still confirm with the breaker against your registration, as ancillary fitment details and any revision changes to the engine during production can vary between applications. Supplying your engine code and VIN gives the breaker the best chance of finding the right part.