S65B40
A 8,300 rpm motorsport-derived V8 with port injection, so no carbon service. The rod bearings are the entire ownership question.
| Configuration | V8, naturally aspirated, individual throttle bodies | Displacement | 3999 cc |
| Fuel | petrol | Injection | port |
| Shared components | none recorded | ||
Cars using this engine
Engine and component issues
Usually silent until it's not. Metal in the oil, then a knock, then a destroyed engine. Tight bearing clearances combined with low-viscosity oil and cold running wear the shells. BMW revised the bearing shells during production.
Check: Ask for a bearing replacement receipt or a recent oil analysis. This is the single question that decides an E9x M3 purchase. A car with documented bearings is worth several thousand more than one without, and it's cheaper to buy the done car.
Later parts: Revised bearing shells fitted later in production; most specialists still treat replacement as preventive maintenance around 100,000 km.
Engine warning light, limp mode, reduced power, actuator fault codes. The individual throttle body actuators wear internally. The V8 has two.
Check: Scan for actuator codes including stored history. Ask whether they've been replaced. Most cars have had at least one.
The car uses oil between services. Up to around a litre per 1,500 km is within BMW's own tolerance. Design characteristic of a high-revving V8, not a fault.
Check: Budget for it and check the level often. Consumption that's suddenly much worse than the car's own history is the warning sign, not consumption itself.
Chassis, gearbox and body issues aren't listed here. They depend on which car the engine is fitted to. Open a variant page for the merged list.