Engine BMW N46B20

Engine BMW N46B20

After the inline four N42B20, BMW began producing a motor with the N46 index, its two-liter modification was named N46B20. It is based on the N42B20 engine, and it seems that the new motor does not differ from the old one at all, but this is only at first glance. In the BMW N46B20 engine, the volume was increased to 2.0 L (1995 cc). Different versions of the engine have different power from 129 to 170 horsepower on average at 6000 rpm, the torque is also different and is 180 or 200 Nm at 3750 rpm.


Manufacturer BMW Plant Hams Hall
Also called N46
Production years 2004-2012
Cylinder block alloy aluminum
Fuel system injector
Configuration inline
Number of cylinders 4
Valves per cylinder 4
Piston stroke, mm 90
Cylinder bore, mm 84
Compression ratio 10.5
Displacement, cc 1995
Power output, hp 129/5750
Torque output, Nm / rpm 180/3250
Fuel type 95
Euro standards Euro 4-5
Weight, kg
Fuel consumption, L/100 km (for 320i E90)
— 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. Excessive consumption of engine oil. As with the N42 series, the main reason is the destruction of the valve stem seals due to prolonged filling of low-quality oil. The oil scraper rings also suffer from this. Both components need to be replaced after 50 thousand kilometers. Bad oil can easily damage the Vanos and Valvetronic systems, KVKG and the oil pump.
  2. Motor jitter. The system for changing the valve timing is clogged – Vanos. Cleaning required.
  3. The appearance of noise and diesel effect. The same reasons as on the N42 version are a loosening of the timing chain or a breakdown of its tensioner. Such ailments appear already after passing 100 thousand kilometers.

Engine BMW N46B20 under the hood
Fifty thousand kilometers of run can be marked by leaking valve cover gaskets and vacuum pump. To avoid most of the engine malfunctions and to make it work harmoniously, like a good clockwork, you can, if you constantly monitor its condition, undergo maintenance on time and fill it with only good oils and fuel.

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