The BMW M52 engine was created in April 1994. This is the second evolution of BMW’s 24-valve engines and is based on the M50TU. The goal of technical development was to reduce weight, emissions and improve torque performance. The most important characteristic of the M52 engine compared to its predecessor M30 and M50 is the aluminum crankcase with Nikasil wear-resistant coating on the cylinder surface (except for the models for North America, which retained the iron block due to the higher sulfur content in the fuel), which is almost 50 % lighter than M50 cast iron block. This resulted in a reduction in engine weight from about 190 kg (M50) to 160 kg (M52).
Specifications
| Manufacturer | Munich Plant |
| Also called | M52 |
| Production years | 1995-2001 |
| Cylinder block alloy | aluminum |
| Fuel system | injector |
| Configuration | inline |
| Number of cylinders | 6 |
| Valves per cylinder | 4 |
| Piston stroke, mm | 75 |
| Cylinder bore, mm | 84 |
| Compression ratio | 10.5 |
| Displacement, cc | 2494 |
| Power output, hp | 170/5500 170/5500 (TU) |
| Torque output, Nm / rpm | 245/3950 245/3500 (TU) |
| Fuel type | 95 |
| Euro standards | Euro 2-3 |
| Weight, kg | ~165 ~175 |
| Fuel consumption, L/100 km (for E36 323i) — city — highway — combined |
13.0 6.7 9.0 |
| Oil consumption, gr/1000 km | up to 1000 |
| Recommended engine oil | 0W-30 / 0W-40 / 5W-30 / 5W-40 / 10W-40 |
| Engine oil capacity, liter | 6.5 |
| Oil change interval, km | 7000-10000 |
| Normal engine operating temperature, °C | ~95 |
| Engine lifespan, km — official information — real |
— ~250 |
Frequent problems
- Overheating. The tendency of the BMW M52B25 engine to overheat can lead to cylinder head distortion. The reason for the rise in temperature is a clogged radiator, air in the cooling system, as well as a malfunction of the thermostat, pump and radiator cap.
- Excessive oil consumption. The reason is increased wear of the cylinder walls or piston rings. Repair – replacement of rings or block sleeve. It can also supply a crankcase ventilation system valve.
- Misfire. The reason is that due to coked hydraulic lifters, the efficiency of the cylinder decreases, followed by its shutdown of the ECU. Repair – replacement of hydraulic lifters.
- Oil pressure lamp is on. The problem is the oil cup or oil pump.
- M52 Vanos. The first signs of vanos wear are rattling and stopping of the engine, a decrease in power and instability of revolutions. Repair – buying a repair kit.
Also, the M52 unit is characterized by: failure of the knee and camshaft sensors, thermostat leakage, poor thread in the cylinder head mount, on average less resource than the M50 series and high sensitivity to gasoline (except for TU models).
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