Characteristics of the N43B20 engine
| Parameter | Value |
|---|---|
| Manufacturing | BMW Plant Hams Hall |
| Engine make | N43 |
| Years of manufacture | 2007-2011 |
| Cylinder block material | aluminum |
| Power system | injector |
| Type | row |
| Number of cylinders | 4 |
| Valves per cylinder | 4 |
| Piston stroke, mm | 90 |
| Cylinder diameter, mm | 84 |
| Compression ratio | 12 |
| Engine displacement, cc | 1995 |
| Engine power, hp/rpm | 122/6000, 143/6000, 170/6700 |
| Torque, Nm/rpm | 185/3000, 190/4250, 210/4250 |
| Fuel | 95 |
| Environmental standards | Euro 4-5 |
| Engine weight, kg | – |
| Fuel consumption, l/100 km | city: 8.3, highway: 5.3, mixed: 6.4 |
| Oil consumption, gr./1000 km | up to 700 |
| Engine oil | 5W-30, 5W-40 |
| How much oil in the engine, liters | 4.25 |
| Oil change is carried out, km | 10000 |
| Engine operating temperature, deg. | – |
| Engine life, thousand kilometers | Factory data: -, in practice: 250+ |
| Tuning, h.p. | potential: 180+, without loss of resource: n.d. |
| Motor installed | BMW 116i E87, BMW 118i E87, BMW 120i E87, BMW 318i E90, BMW 320i E90, BMW 520i E60 |
Reliability, problems and repair of the BMW N43B20 engine
Another successor to the N42B20, released 3 years after it was taken off the assembly line, is a 2-liter engine with some modifications. Unlike the old N42, direct fuel injection has been added here, and the Valvetronic valve height modification system is gone. The pistons have also been changed and the compression ratio has been increased to 12. The engine is controlled via a Siemens MSD 81.2 system.
The engine was available in three variants:
- N43B20K0 – programmatically stifled version with 122 hp at 6000 rpm and 185 Nm of torque at 3000 rpm. This motor was fitted to the 16i version of the BMW.
- N43B20U0 – version for BMW models with index 18i, with an output of 143 hp at 6000 rpm and torque of 190 Nm at 4250 rpm.
- N43B20O0 is the most powerful version for BMW models with the 20i index. It produces 170 hp at 6,700 rpm and 210 Nm of torque at 4,250 rpm
Based on this power unit, a smaller displacement motor N43B16 with a different crankshaft and piston was also produced. Along with the N43, other four-cylinder followers of the N42 were produced, the N45B20S and N46B20.
In 2011, BMW’s turbocharging era almost completely took over, and the N43B20 was replaced by the 1.6-liter, turbocharged N13B16.
Problems and drawbacks of BMW’s N43B20 engines:
- Engine vibration, often caused by injector problems.
- Trottling and floating revs of the N43 engine, which are usually due to ignition coil problems.
- Vacuum pump begins to leak after 60-80 thousand kilometers and requires replacement.
- The need to monitor the condition of the cooling system to prevent overheating.
In addition, the N43 engine is very sensitive to the quality of fuel and especially oil. The use of quality oil recommended by BMW will help to avoid unpleasant consequences. With proper care and timely maintenance, the N43B20 engine will last a long time and practically without problems.
Tuning of BMW N43B20 engine
Chip tuning
Similar to its predecessor, there is also no inarticulate tuning on the N43 and the only way out is re-flashing. Aggressive tuning together with sports exhaust can add a sense of dynamics and about 10-15 hp. It is very difficult to go further and if these figures are not impressive, and speed wants, then it is worth considering the purchase of a more powerful BMW, with N54/N55 for example.
MOTOR RATING: 4+