The 4-cylinder N42B20 engine replaced the obsolete M43B18, M43B19 and M44B19 in 2001. Instead of a heavy cast-iron cylinder block, a light aluminum one with cast iron liners was used in the new engine.
The N42B20 engine uses a new long-stroke crankshaft (90 mm stroke) as well as new pistons and connecting rods. The balance shafts remain the same as on the M43TU and fitted to the new block.
Instead of the previous SOHC 8V cylinder head, a new twin-shaft 16-valve with a timing block was used. In addition, the new cylinder head is equipped with a variable valve timing system on both Double-VANOS shafts, as well as a Valvetronic intake valve lift system. The diameter of the intake valves is 32 mm, exhaust 29 mm. Characteristics of standard BMW N42 camshafts: phase 250/258, rise to 9.7/9.7.
The intake manifold of the N42B20 is equipped with a DISA variable length system, which greatly optimizes performance at both low and high speeds. Bosch ME 9.2 engine management system.
This motor was used on BMW cars with the 18i index.
N42 family: N42B18, N42B20.
Specifications
| Production years | 2001-2004 |
| Displacement, cc | 1995 |
| Fuel system | injector |
| Power output, hp | 143 /6000 rpm |
| Torque output, Nm | 200 /3750 rpm |
| Cylinder block | aluminum R4 |
| Block head | aluminum 16v |
| Cylinder bore, mm | 84 |
| Piston stroke, mm | 90 |
| Compression ratio | 10.0 |
| Features | Valvetronic |
| Hydraulic lifters | yes |
| Timing drive | chain |
| Phase regulator | double VANOS |
| Turbocharging | no |
| Recommended engine oil | 5W-30 |
| Engine oil capacity, liter | 4.25 |
| Fuel type | petrol |
| Euro standards | EURO 3 |
| Fuel consumption, L/100 km (for BMW 318i 2002) — city — highway — combined |
10.0 5.5 7.2 |
| Engine lifespan, km | ~275 000 |
| Weight, kg | 120 |
The engine was installed on:
- BMW 3-Series E46 in 2001 – 2004.
Disadvantages of the N42B20 engine
- Most of the problems for owners are caused by failures in Valvetronic and Vanos systems;
- The timing chain and its tensioner often require replacement already at a range of 100 – 150 thousand km;
- The engine is very hot, which greatly affects the life of the valve stem seals;
- Non-original oil may not withstand these temperatures and the engine will seize;
- When replacing candles, expensive ignition coils very often fail here.
Frequently asked questions about the BMW N42B20
How much power does the BMW N42B20 make?
Power output of the BMW N42B20, hp: 143 /6000 rpm. Torque, Nm: 200 /3750 rpm.
How much oil does the BMW N42B20 take and which one?
Engine oil capacity: 4.25 liters. Recommended oil: 5W-30.
Does the BMW N42B20 have a timing belt or chain?
The BMW N42B20 uses a timing chain.
Is the BMW N42B20 turbocharged?
No, the BMW N42B20 is naturally aspirated.
Does the BMW N42B20 need valve clearance adjustment?
No, the BMW N42B20 has hydraulic lifters, so the valve clearances do not need to be adjusted.
How long does the BMW N42B20 last?
The typical lifespan of the BMW N42B20 is ~275 000 km with proper maintenance.
What is the fuel consumption of the BMW N42B20?
BMW 318i 2002: city 10.0, highway 5.5, combined 7.2 L/100 km.
What cars was the BMW N42B20 installed on?
BMW 3-Series E46 in 2001 - 2004.
What are the common problems of the BMW N42B20?
Most of the problems for owners are caused by failures in Valvetronic and Vanos systems. The timing chain and its tensioner often require replacement already at a range of 100 - 150 thousand km. All known problems.
What engines are related to the BMW N42B20?
N42 family: N42B18.
