The M54B25 is a very popular 2.5 liter engine in the M54 series (which includes the M54B22, M54B30 and S54B32) and entered the BMW production line in 2000 and replaced the M52TUB25.
Differences between the M54 and the M52: the cylinder block of the new engine remained old, aluminum with cast-iron sleeves and with a cast-iron crankshaft, connecting rods (145 mm) changed, light pistons appeared. The cylinder head remained the same with double vanos, the long intake manifold was replaced with a new short one (-10 mm from M52TU) with wide DISA channels, which made it possible to increase power and let the engine breathe freely. In addition, a 64 mm electronic throttle and a Siemens MS43/Siemens MS45 control system (Siemens MS45.1 for US) are used.
This motor was used on BMW cars with an index of 25i.
Specifications
| Production years | 2000-2006 Munich Plant |
| Displacement, cc | 2494 |
| Fuel system | injector |
| Power output, hp | 192 |
| Torque output, Nm | 245 |
| Cylinder block | aluminum R6 |
| Block head | aluminum 24v |
| Cylinder bore, mm | 84 |
| Piston stroke, mm | 75 |
| Compression ratio | 10.5 |
| Features | DISA |
| 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 3/4 |
| Fuel consumption, L/100 km — city — highway — combined |
14.0 7.0 9.4 |
| Engine lifespan, km | ~320 000 |
| Weight, kg | ~130 |
Disadvantages of the M54B25 engine
With long-term operation, even reliable BMW M54B25 engines can experience problems with overheating, misfiring, and high oil consumption.
If the engine overheats, see if the radiator needs to be cleaned, check the condition of the thermostat and the radiator cap. Helps to expel air from the cooling system.
High oil consumption in engines is associated with coking of the piston rings. We need to put on new rings. Also check the crankcase ventilation valve, it may need to be replaced.
When misfires are noticeable, the reason is the hydraulic lifters that need to be replaced.
If the red oil light is constantly on, you need to check the oil pump and oil cup. Another common problem is the failure of the camshaft position sensor. It should be borne in mind that the thread under the cylinder head is not highly reliable.
Timely diagnostics and replacement of worn parts will ensure the convenience and reliability of engine operation.
