N53B25
BMW N53B25 Engine
N53B25 Specs
| Manufacturer | Munich Plant |
| Also called | BMW N53 |
| Production | 2007-2010 |
| Cylinder block alloy | Aluminium-magnesium |
| Configuration | Straight-6 |
| Valvetrain | DOHC 4 valves per cylinder |
| Piston stroke, mm (inch) | 78.8 (3.1) |
| Cylinder bore, mm (inch) | 82 (3.23) |
| Compression ratio | 12 |
| Displacement | 2497 cc (152.4 cu in) |
| Power output | 140 kW (190 HP) at 6,100 rpm 140 kW (190 HP) at 6,300 rpm |
| Torque output | 235 Nm (173 lb·ft) at 3,500-5,000 rpm 240 Nm (177 lb·ft) at 3,500-5,000 rpm |
| Redline | 6,500 rpm |
| HP per liter | 76.1 |
| Fuel type | Gasoline |
| ECU | Siemens MSD80 |
| Weight, kg (lbs) | ~115 (254) |
| Fuel consumption, L/100 km (mpg) -City -Highway -Combined |
for E60 523i 10.0 (23.5) 5.7 (41.3) 7.3 (32.2) |
| Turbocharger | Naturally aspirated |
| Oil consumption , L/1000 km (qt. per miles) |
up to 1.0 (1 qt. per 750 miles) |
| Recommended engine oil | 5W-30 5W-40 |
| Engine oil capacity, L (qt.) | 6.5 (6.9) |
| Oil change interval, km (miles) | 7,000-10,000 (4,500-6,000) |
| Normal engine operating temperature, °C (F) | ~95 (203) |
| Engine lifespan, km (miles) -Official information -Real |
– ~250-300 (155-185) |
| Tuning, HP -Max HP -No life span loss |
230+ – |
| The engine is installed in | BMW 523i E60 |
BMW N53B25 engine reliability, problems and repair
This is new version of inline 6-cylinder engine from N53 generation which also includes N53B30 motor. It was produced on base of N52B25 and was firstly introduced in 2007. The block of cylinders is the same with minimum changes. Pistons were improved providing 12 compression ratio.
Double-VANOS cylinder block head was also improved. It was additional equipped with direct injection. Valvetronic was no longer used by BMW engineers. At the same time engine control unit was also changed. Siemens MSV70 was replaced by Siemens MSD81. The rest of engine components are the same.
This engine was used in BMW 23i models.
N53B25 successor was introduced in 2011. It was N20B20 4-cylinder turbocharged engine.
BMW N53B25 engine problems and drawbacks
This engine does not have any serious problems. The most common malfunctions may include high-pressure fuel pump (HPFP) which occurs after 60 000 miles (100 000 km) of mileage, spark plugs of low durability (needs replacement after 6 000 miles/10 000 km of mileage), coil of low reliability which needs replacement every 30,000 miles (50,000 km) of mileage and high pressure fuel injectors (needs replacement after 60,000 miles/100,000 km of mileage).
At the same time this engine calls for high quality fuel and motor oil. Owners of BMW models with N53 under its bonnet are also recommended to proceed with regular check of cooling system as well as radiator cleaning in order to prevent engine from overheating. You will not face problems of high level of oil consumption as in N52B52. That is why total N53 lifespan is longer in comparison with previous generation of motors.
BMW N53B25 engine tuning
N53B25 Chip-tuning
Just as its predecessor N52, N53 engine is not the best choice for tuning. The only way to increase the level of power is to use additional firmware and ECU along with performance exhaust system. Such modifications will make it possible to add extra 10-15 HP as well as improve sound effects when the engine is operating.
If you need much more powerful unit, the best bet is to purchase BMW N53B30 engine with 272 HP and install it on your auto or buy BMW model equipped by N54.
