The N53B25 inline 6-cylinder engine represents the N53 family (also includes the N53B30), developed on the basis of the N52B25 and in 2007 was intended to replace the raw predecessor. The cylinder block remained the same with minimal changes, the pistons changed and the compression ratio increased to 12. The cylinder head with Double-VANOS was finalized, a direct fuel injection system appeared, and the Valvetronic valve lift change system disappeared. The engine control system has changed, now Siemens MSD81 is used instead of Siemens MSV70, otherwise the motor is the same. This motor was used on BMW cars with the 23i index.
Specifications
| Production years | 2007-2010 |
| Displacement, cc | 2497 |
| Fuel system | direct injection |
| Power output, hp | 190 |
| Torque output, Nm | 235 – 240 |
| Cylinder block | aluminum R6 |
| Block head | aluminum 24v |
| Cylinder bore, mm | 82 |
| Piston stroke, mm | 78.8 |
| Compression ratio | 12.0 |
| Features | no |
| Hydraulic lifters | yes |
| Timing drive | chain |
| Phase regulator | double VANOS |
| Turbocharging | no |
| Recommended engine oil | 5W-30 |
| Engine oil capacity, liter | 6.5 |
| Fuel type | petrol |
| Euro standards | EURO 5 |
| Fuel consumption, L/100 km (for E60 523i) — city — highway — combined |
10.0 5.7 7.3 |
| Engine lifespan, km | ~275 000 |
Disadvantages of the N53B25 engine
- Most of the problems with this unit are related to the direct fuel injection system.
- From bad gasoline, piezoelectric injectors and their high pressure fuel pump quickly fail.
- After a long stop, faulty injectors can cause water hammer in the motor.
- Also, owners of cars with this engine often change spark plugs and ignition coils.
- On runs over 100,000 km, the Vanos phase control system often requires repair.
