BMW N42B20 engine

Gasoline engine with a displacement of 1995 cubic centimeters. Produced for 5 years, since 2001. It has an in-line structure with an injector feeding system. The cylinder blocks are made of aluminum. The motor has 16 valves, 4 for each cylinder. The stroke of the piston is 90 millimeters. The diameter of each of the 4 cylinders is 84 millimeters. It is recommended to use 95 fuel. Meets Euro 3 environmental standards. Maximum power of the two-liter N42B20 is 143 horsepower, torque 200 NM. The compression ratio is 10 to 1. The weight of the motor is about 120 kilograms.

On the highway consumes 5.5 liters per 100 kilometers. In the city about 10 liters. In mixed mode, the engine consumes about 7.2 liters. At 1000 kilometers spends 500 – 700 grams of oil. The motor holds 4.25 liters of oily liquid. In case of oil change it is required to refill 4 liters. Replacement is made once every 10 thousand kilometers. Engine resource in practice is more than 250 thousand kilometers.  With tuning, the engine has a capacity of more than 150 horsepower. It is recommended to use oil 5W-40 or 5W-30.

N42B20 engine specifications

Advantages

The N42B20 replaced the M44B19. The main difference is the use of aluminum for the cylinder block. The versions before that used cast iron. The motor is characterized by an increased piston stroke, up to 90 millimeters. More advanced connecting rods are also used. Balanced shafts remain the same.

Instead of the outdated SOHC8V cylinder head, a new system with 16 valves and a timing block is used. The modernized cylinder head also has a gas distribution phase change system. A Double Vanos system is used along with Valvtronic, which is responsible for lifting the intake valves. The hydraulic compensators remain the same. N42B20 has a DISA system, which optimizes the engine’s performance at low and high speeds. Bosch version 9.2 is used to control the motor. In 2004, the N42B20 gave way to its modified version N45B20S.

Disadvantages

The most common disadvantage of the N42B20 is overheating. It is explained by a dirty radiator or a failed thermostat. The service life of the latter is about 100 thousand kilometers.  As a result, the oil caps fail and oil consumption increases. The owner of N42B20 needs to carefully monitor the cooling system.

Some people notice noises in the engine. This is explained by the stretching of the chain, the life of which is about 100 thousand kilometers. When replacing the plugs, the ignition coils may fail. It is recommended to install EPA instead of them. This motor is demanding to oil, it is required to follow the manufacturer’s instructions. Saving on oil you will have to spend much more on engine overhaul. N42B20 is quite economical motor, but it is less reliable.

Chip Tuning

Any versions of the N42 are difficult to tuning. In market conditions it is problematic to find parts to increase power. The only possible option is to change the air filter. It is recommended to put a filter with lower resistance. Thus, the power will increase to 160 horsepower, which is almost imperceptible on the highway. With a sport exhaust it will be possible to add a sense of power gain. It is very difficult to make something worthwhile with the N42B20. It’s easier to buy an E46.

This engine is installed on the following models:

BMW 3-Series (E46)