Characteristics of M52B25 engine
| Characteristics | M52B25 | M52B25TU / M52TUB25 |
|---|---|---|
| Fine volume | 2494 cm³ | 2494 cm³ |
| Power System | Injector | Injector |
| Power | 170 hp | 170 hp |
| Torque | 245 Nm | 245 Nm |
| Cylinder block | Aluminum R6 | Aluminum R6 |
| Cylinder head | Aluminum 24v | Aluminum 24v |
| Cylinder diameter | 84 mm | 84 mm |
| Piston stroke | 75 mm | 75 mm |
| Compression ratio | 10.5 | 10.5 |
| Engine Features | No | No |
| Hydrocompensators | Yes | Yes |
| Transmission timing | Chain | Chain |
| Phase regulator | Single VANOS | Double VANOS |
| Turbocharger | No | No |
| Recommended oil | 6.5 liters | 6.5 liters |
| Environmental class | EURO 2 | EBRO 3 |
| Example service life | 300,000 km | 350,000 km |
Main differences:
- The M52B25TU uses Double VANOS, which adjusts the phases at the intake and exhaust.
- The environmental class of M52B25TU is higher – EURO 3 (in M52B25 – EURO 2).
- The service life of the M52B25TU is increased by 50,000 km (up to 350,000 km).
The engine was installed BMW 323i E36
- BMW 323i E46
- BMW 523i E39
- BMW Z3
Reliability and repair of BMW M52B25 engine
BMW M52B25 engine from the new M52 family (it included M52B20, M52B24, M52B28, S52B32) was introduced in 1995 and positioned as a replacement for the 2.5-liter representative of the M50. The bottom end geometry remained the same, but the cast iron block was replaced by a lightweight aluminum block with Nicasil coated cylinders, pistons and connecting rods were changed. The length of the M52B25 connecting rod is 140 mm, compression height of the piston is 32.55 mm. A different intake system was used. The cylinder head has been transferred from M50 Vanos and now the variable valve timing system is used on all engines. The injectors on the M52B25 are 190 cc.
In 1998, the engine underwent some improvements and was named M52TUB25 (Technical update). Among the innovations are the appearance of cast iron liners in the cylinder block and the second phase shifter on the exhaust shaft (Double-VANOS), other camshafts 244/228 lift 9/9 mm, pistons and connecting rods, new intake manifold disa, modified cooling system, electronic throttle.
Due to the fact that this power unit turned out to be more torquey and not as powerful as the M50B25, it was used in BMW cars with the index 23i.
Since 2000, the BMW M52B25 engine began to be replaced by a new representative of 2.5-liter sixes – M54B25 and in 2001 this process was completely completed.
Modifications of BMW M52B25 engine
- M52B25 (1995 – 1999) – basic engine. Compression ratio 10.5, power 170 hp at 5500 rpm, torque 245 Nm at 3950 rpm.
- M52TUB25 (1998 – 2001) – VANOS timing system was improved and received a second phase shifter at the exhaust and became known as Double-VANOS. Cast iron liners were added to the cylinder block, the connecting rod and piston group was changed, and other camshafts were installed. Compression ratio 10.5, power 170 hp at 5500 rpm, torque 245 Nm at 3500 rpm.
Problems and disadvantages of BMW M52B25 engines
- Overheating. Like the M50 series, the M52 engine is prone to overheating. If the engine has started to warm up, it is necessary to clean the radiator, expel air from the cooling system, check the pump, thermostat and radiator cap.
- Oil burn. In M52 engines are very susceptible to wear piston rings, if the cylinder walls are in order, then you can do without replacing the rings, it is enough for now. In case of their wear, give the block to liner (for nikasilovyh motors). In addition, check the crankcase ventilation valve (CVCG).
- Ignition misses. The problem lies in the hydrocompensators, as a result of which the performance of the cylinder drops and the ECU disconnects it. Buy and change hydrocompensators, everything will work.
- The oil light is on. Usually the problem lies either in the oil cup or oil pump, check.
- M52 Vanos. If there is rumbling, power drop and floating revs (sometimes the motor stalls), there is a probability of vanos wear. Repair is simple: you need to buy a repair kit vanos M52.
In addition, often fail crankshaft position sensors DPKV (does not start M52) and camshaft (DPRV), unreliable threads under the bolts fixing the cylinder head, leaks thermostat, high demanding the quality of gasoline (For non TU versions), the average life is lower than that of the predecessor M50 and so on. In addition, given the nature of ownership of BMW engines and serious age, you can expect anything and anytime, this motor is not the best choice for purchase.
For swap and tuning, it is better to buy BMW M50B25 Non Vanos or M54B30.
Tuning the BMW M52B25 engine
Stroker
The most trivial way to increase the power of the BMW M52B25 engine is to buy a cold intake, intake manifold from M50B25, camshafts with a small phase 250/250 lift 10 mm and do chip tuning. As a result we will get about 210-220 hp.
You can go the other way and increase the working volume to 2.8 liters by installing a stroker kit in the cylinder block. To do this, you need to buy a crankshaft and connecting rods from M52B28, leave the pistons standard, the firmware will fit from M52B28. And to make this M52B25 2.8 go properly, you need to put the intake from M50B25, camshafts and exhaust from S52, adjust and enjoy the powerful motor.
M52B25 Turbo
To turbocharge an M52B25, all you need to do is repeat all of the procedures performed to supercharge an M50B25. You can read more about it here.
MOTOR RATING: 4