Engine BMW N43B20

The BMW N43B20 engine is a 4-cylinder inline gasoline unit produced by BMW from 2007 to 2011. There are three versions of the N43 engine, which have gained popularity and recognition among motorists around the world.

  1. N43B20K0 – software-strangled version with 122 hp at 6000 rpm, 185 Nm of torque at 3000 rpm. The motor was installed on the BMW version with the index 16i.
  2. N43B20U0 – version for BMW models with the index 18i, power 143 hp at 6000 rpm, torque 190 Nm at 4250 rpm.
  3. N43B20O0 – the most powerful version for BMW models with the 20i index. Power 170 hp at 6700 rpm, torque 210 Nm at 4250 rpm.

Unlike its predecessor, the N42 engine, the new BMW N43 engine features direct fuel injection and Valvetronic valve lift systems. The engine was produced in conjunction with such units as N45 and N46, however, in terms of demand, it surpassed its followers in this period of time.

This engine has been designed to achieve an optimally high level of torque combined with economy and environmental friendliness – a combination that is not always easy to achieve.


Production years 2007-2011
Displacement, cc 1995
Fuel system direct injection
Power output, hp 122 /6000 rpm
143 /6000 rpm
170 /6700 rpm
Torque output, Nm 185 /3000 rpm
190 /4250 rpm
210 /4250 rpm
Cylinder block aluminum R4
Block head aluminum 16v
Cylinder bore, mm 84
Piston stroke, mm 90
Compression ratio 12.0
Features no
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 4/5
Fuel consumption, L/100 km (for 320i E90)
— city
— highway
— combined
Engine lifespan, km ~250 000

Disadvantages of the N43B20 engine

  1. Vibrations of the motor housing. This breakdown often manifests itself on the N43 due to the failure of the injectors. Therefore, a complete replacement of the latter will be required.
  2. Trocking and interruptions in engine speed. The cause of the breakdown is the failed ignition coils. Replacement required.
  3. Leaking vacuum pump. Such a disadvantage often appears every 70 thousand km of the distance traveled. The only way to fix the problem is to replace the device.

The cooling system always needs to be checked, otherwise it is easy to overheat. In addition, the power unit of this series is quite demanding on oil and fuel. Oil requires particularly careful quality control. High-temperature operation of the engine will immediately lead to the deterioration of uncertified oil, which in the future will lead to big problems. Therefore, it is recommended to use only the oil recommended by the manufacturer for N43B20. Proper care and timely maintenance will make the engine run longer than its intended resource.

1 thought on “Engine BMW N43B20”

  1. Βασιλικη Καπετανιδου

    Ο κινητηρας Ν43Β20 ειναι τα σταθερα στοιχεια του κινητηρα?Οταν ειναι χαραγμενα στον κινητηρα τα εξης:Ν43Β20ΑD τοτε για ποια ηπειρο ηταν αυτος ο κινητηρας ο οποιος καιει φτωχο μειγμα?

    Google translate: The engine N43B20 is the fixed elements of the engine? When the following are written on the engine: N43B20AD then for which continent was this engine that burns a lean mixture?

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