BMW N42B18 under the hood

Engine BMW N42B18

BMW N42B18 engines are in-line 4-cylinder engines with DOHC gas distribution system. The predecessor of this unit model was the M43 series engines. The main feature of the N42B18 is the two overhead camshafts and the innovative VANOS system. This technology made it possible to reduce fuel consumption and reduce outlet gas pollution. And Valvetronic technology contributes to increased power by optimizing the cylinder filling with the mixture.


Manufacturer BMW Plant Hams Hall
Also called N42
Production years 2001-2004
Cylinder block alloy aluminum
Fuel system injector
Configuration inline
Number of cylinders 4
Valves per cylinder 4
Piston stroke, mm 81
Cylinder bore, mm 84
Compression ratio 10.5
Displacement, cc 1796
Power output, hp 116/5500
Torque output, Nm / rpm 175/3750
Fuel type 95
Euro standards Euro 3
Weight, kg 120
Fuel consumption, L/100 km (for 316i E46)
— city
— highway
— combined
Oil consumption, gr/1000 km up to 700
Recommended engine oil 5W-30 / 5W-40
Engine oil capacity, liter 4.25
Amount of engine oil for replacement, liter 4
Oil change interval, km 10000
Normal engine operating temperature, °C
Engine lifespan, km
— official information
— real


Frequent problems

  1. Temperature rise. The main reason is poor cleaning of the radiator, a damaged thermostat, which just needs to be changed after every 100 thousand km of run. The consequence of this is the failure of the valve stem seals. As a result, the unit consumes excessive oil. Therefore, you should always inspect the cooling system.
  2. Noise, diesel. The breakage must be repaired by completely replacing the chain tensioner. Its term is plus or minus 100 thousand km. You also need to check the timing chain, which at the same time can stretch and lead to an increase in noise.

BMW N42B18 engine
You also need to take into account that when changing spark plugs, the coils of the BREMI ignition system often deteriorate. It is better to change the latter to EPA. The N42’s powertrain loves good oils. It is better to pour only the one recommended by the manufacturer itself. The engine has a high heating temperature, and saving on oil, as a rule, leads to the need for overhaul. Often it will be necessary to replace the vanos as well.

The motor is quite economical and functional, however, it is also very capricious (it needs to be constantly monitored), and not as reliable as its predecessors, that is, the M40-M43.

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