The N42B20 engine is an inline four-cylinder engine from BMW, produced from 2001 to 2004. Its features include a lightweight aluminum cylinder block, a high level of technology and Euro 3 environmental standards. The engine combines economy and sufficient power for everyday use.
Characteristics of the N42B20 engine
| Characteristics | Reference |
|---|---|
| Manufacturing | BMW Plant Hams Hall |
| Engine make | N42 |
| Years of production | 2001-2004 |
| Cylinder block material | Aluminum |
| Power system | Injector |
| Engine type | Ready |
| Number of cylinders | 4 |
| Valves per cylinder | 4 |
| Piston stroke, mm | 90 |
| Cylinder diameter, mm | 84 |
| Compression ratio | 10 |
| Engine displacement, cc | 1995 |
| Power, hp/rpm | 143/6000 |
| Torque, Nm/rpm | 200/3750 |
| Environmental standards | Euro 3 |
| Engine weight, kg | 120 |
| Oil consumption, gr./1000 km | Up to 700 |
| Oil volume in the engine, l | 4.25 |
| Recommended oil | 5W-30, 5W-40 |
| Engine life, thousand kilometers | Factory: – In practice: 250+ |
| Tuning potential, hp | Potential: 150+ Without loss of resource: n.a.d. |
Engine Application
The N42B20 engine was installed in the following BMW models:
- BMW 318i (E46)
Design and repair of the BMW N42B20 engine
Another in-line four-cylinder engine N42B20 began to be installed on Bavarian cars in 2001 and replaced the outdated fours M43B18, M43B19 and M44B19. Instead of a heavy cast iron cylinder block, the new engine began to use a lightweight aluminum one with cast iron liners. The N42B20 engine uses a new long-stroke crankshaft (90 mm stroke), as well as new pistons and connecting rods. The balancer shafts remain the same as on the M43TU and are matched to the new block.
Instead of the previous SOHC 8V cylinder head, a new twin-shaft 16-valve cylinder head with timing block is used. In addition, the new cylinder head features Double-VANOS dual-shaft timing, as well as Valvetronic intake valve lift height modification. Things like hydrocompensators haven’t gone anywhere and are still used on the N42. The diameter of the intake valves is 32mm and the exhaust valves are 29mm. Characteristics of standard BMW N42 camshafts: phase 250/258, lift to 9.7/9.7.
The N42B20 intake manifold is equipped with the DISA length modification system, which significantly optimizes performance at both low and high speeds. The engine management system is Bosch ME 9.2.
This motor was used in BMW cars with the index 18i.
A younger 1.8-liter version with a short-stroke crankshaft – N42B18 – was produced on the basis of this power unit.
In 2004, the N42B20 was replaced by new engines N45B20S and N46B20, and in 2007, the third successor – N43B20.
Problems and disadvantages of BMW N42B20 engines
- Overheating. The cause of overheating of N42 is in the radiator, which nobody ever cleans, or in a dead thermostat, the life of which is +/- 100 thousand kilometers. As a result, the oil caps die and the N42 starts eating oil in obscene amounts. Always keep an eye on the cooling system.
- Noise, diesel. Often the problem is solved by replacing the chain tensioner, which runs +/- 100 thousand kilometers. In addition, the timing chain on the N42 is not too reliable and at +/- 100 thousand km, it may well stretch and make noise.
In addition, when replacing the plugs can fail and ignition coils BREMI, in which case they should be replaced with EPA. The N42 engine has high requirements to the quality of oil, ideally use the oil recommended by the manufacturer. Saving on oil in such a hot engine can easily lead to overhaul, replacement of vanos and other joys.
As a result, it turned out to be quite technological and economical, but very capricious motor, less reliable than predecessors M40-M43, requiring constant control and quality service.
Tuning BMW N42B20 engine
Chip tuning
Engines of N42 family are very badly subjected to tuning, there are no corresponding spare parts on the market and the only way out in this situation is chip-tuning with replacement of air filter with low resistance filter. These modifications will increase the output to ~160 hp, which is very difficult to feel. By adding a sport exhaust, you can slightly increase the feeling of additional hp.
To do something powerful on the basis of N42 is difficult and very expensive, it is easier to immediately replace the car with an M3 E46.
MOTOR RATING: 4