Crankshaft bearing wear, oil pump failure and engine rebuild specialists. The truth about one of BMW’s most talked-about issues — from a team that rebuilds these engines every week.
An engine knock means bearing failure has already begun. Every mile driven is causing further damage to the crankshaft, block and oil system. Stop driving the vehicle and contact us straight away. The sooner we can assess it, the more we can save.
The BMW N57 is one of BMW’s highest-output diesel platforms — producing up to 740Nm of torque in tri-turbo form. That exceptional torque is transmitted directly through the crankshaft into the main and connecting rod bearings. Higher torque means higher bearing load. That is mechanical fact.
BMW’s Condition Based Servicing allows oil change intervals of 18,000–20,000 miles — sometimes up to 24 months. Modern diesel engines inherently introduce soot contamination, fuel dilution during DPF regeneration and increased oil shear under high cylinder pressure. As oil degrades, the hydrodynamic oil film that the crankshaft bearings rely on thins. In a high-torque engine, accelerated bearing wear is the result.
The N57 was also engineered with tight bearing clearances to improve efficiency and reduce friction — but this means there is less tolerance for degraded oil condition. Combined with strong low-RPM torque delivery between 1,500 and 2,000 RPM, peak loading on the upper bearing shells is significant.
It makes no difference to us financially whether we replace bearings preventatively or after failure — we make the same amount of money either way. Only the customer is worse off. We have no interest in selling work that isn’t needed.
The seriousness of this issue is not in question. The Police withdrew their contract from BMW for emergency vehicles following bottom end failures that contributed to the death of an officer. This is a well-documented, inherent issue with this engine platform.
Higher torque output equals higher bearing load. The twin and tri-turbo variants are most prevalent for bottom end issues — though all N57 engines should be considered at risk.
Engine knock or rattle — particularly at low RPM or on startup
Metal particles in oil or filter — a critical warning sign
Low oil pressure warning — act immediately
No warning at all — many engines fail without any prior symptoms. Do not wait for a knock before acting.
Engines maintained on reduced oil service intervals of 8–10,000 miles using the correct specification oil show significantly lower wear rates. This alone is the single most effective thing you can do to protect your N57 engine.
All prices exclude VAT. Engine removal is required for all N57 bottom end work. All work uses genuine BMW parts only — no aftermarket crankshafts, no aftermarket bearings, no aftermarket oil pumps.
OEM IWIS timing chain kit, new main & big end bearings and new BMW oil pump — all carried out together in one engine removal. The bearing and oil pump work is only available as part of this combined service — not as a standalone. Next day service. Minimum 12 month / 20,000 mile warranty included.
Complete engine rebuild once bottom end failure has occurred. New BMW crankshaft, line-bored block, new bearings, new oil pump, OEM IWIS timing chain kit, reconditioned head and gasket set.
Preventative: from £2,500 + VAT. Full rebuild after failure: £6,500 + VAT.
The difference is £4,000 + VAT — and that assumes no further damage to turbos, head or block.
Full engine removal from the vehicle. Complete strip down to assess the extent of bearing wear and any secondary damage to crankshaft, block and oil circuit.
The bare block is sent to a specialist machine shop to verify that the main bearing housings are perfectly straight and round. If not, they are line-bored to correct specification.
We only ever fit a new genuine BMW crankshaft. The N57 crankshaft is nitrided surface hardened — grinding removes this layer and causes rapid re-failure. We do not use aftermarket crankshafts.
New OEM main and big end bearings, new BMW oil pump, new OEM IWIS timing chain kit, reconditioned cylinder head with new gasket set, reconditioned turbos where required.
Re-grinding is standard practice on older engines — but not on the N57. The N57 crankshaft is nitrided surface hardened. Grinding removes this hardened layer, fundamentally weakening the crankshaft and causing it to fail again quickly. We have seen hundreds of engines re-ground and returned to us knocking or seized shortly after. We will only ever fit a new genuine BMW crankshaft.
We’ll identify your exact BMW model, engine and year — then show you a tailored price.
Sourced from official DVLA & DVSA records