N20B20 Engine Review: Specs, Problems and Reliability


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In 2011, BMW started to produce its N20B20 turbocharged four-cylinder engine, which was meant to be used instead of six-cylinder N53B25 and N53B30 inline engines.

The engine features an aluminum cylinder block, which has two balance shafts and cylinders with steel armour. Moreover, the engine features a forged crankshaft with four counterbalances planted with offset. The length of connecting rods, which are almost identical to BMW N55, is 144.35 mm. Also, the N20B20 features FM pistons with a negative shift of the piston ring.

Another similarity of N20B20 and N55 engines is the cylinder head with Valvetronic III, a variable timing system employed in combination with the Double-VANOS system on the intake and exhaust camshafts. In addition, the N20B20 engine has the Turbocharged Valvetronic Direct Injection system, which is also known as TVDI.

The N20 engine, which features the Twin Scroll Turbo System by Mitsubishi TD04LR6-04HR.15TK31-60T, has a boost pressure of 17 psi (1.15 bar).

The intake manifold of N20 resembles the one of the N55 engines.

The N20 engine employs the Bosch MEVD17.2.4.system.

Breakdown of N20 engine designation:

  • N – BMW Group Development
  • 2 – 4-cylinder in-line engine
  • 0 – Engine with exhaust turbocharger, Valvetronic and direct fuel injection (TVDI)
  • B – Gasoline engine, longitudinally installed
  • 20 – 2.0 litres displacement
  • O – upper-performance class
  • 0 – New development

High-quality parts

BMW N20B20 Engine Specs

Manufacturer BMW Plant Hams Hall
Also called BMW N20
Production 2011-present
Cylinder block alloy Aluminum
Configuration Straight-4
Valvetrain DOHC
4 valves per cylinder
Piston stroke, mm (inch) 90.1 (3.55)
Cylinder bore, mm (inch) 84 (3.31)
Compression ratio 10
11
Displacement 1997 cc (121.9 cu in)
Power output 115 kW (156 HP) at 5,000 rpm
135 kW (184 HP) at 5,000 rpm
160 kW (218 HP) at 5,500 rpm
180 kW (245 HP) at 5,000 rpm
Torque output 240 Nm (177 lb·ft) at 1,250-4,500 rpm
270 Nm (199 lb·ft) at 1,250-4,500 rpm
310 Nm (229 lb·ft) at 1,350-4,800 rpm
350 Nm (258 lb·ft) at 1,250-4,800 rpm
Redline 7,000 rpm
HP per liter 78.1
92.1
109.2
122.7
Fuel type Gasoline
Fuel system Bosch MEVD17.2.4
Weight, kg (lbs)
Fuel consumption, L/100 km (mpg)
-City
-Highway
-Combined
for F30 328i
8.5 (27.7)
5.2 (45.2)
6.4 (36.8)
Turbocharger Mitsubishi TD04LR6-04HR.15TK31-60T
Oil consumption, L/1000 km
(qt. per miles)
up to 0.7
(1 qt. per 850 miles)
Recommended engine oil 5W-30
5W-40
Engine oil capacity, L (qt.) 5 (5.3)
Oil change interval, km (miles) 7,000-10,000
(4,500-6,000)
Normal engine operating temperature, °C (F)
Engine lifespan, km (miles)
-Official information
-Real

250+ (155)
Tuning, HP
-Max HP
-No life span loss
300+

 

Setting of map thermostat Coolant temperature
Starts to open 97 C / 206 F
Fully open 109 C* / 228 F

 

BMW N20B20 Engine Modifications

  1. N20B20O0 (since 2011) is the basic type of engine applied for BMW 28i cars. Its compression ratio is 10, while its boost pressure is 17 psi (1.15 bar). The N20B20O0 reaches 245 hp at 5,000 rpm and 350 NM at 1,250-4,800 rpm.
  2. N20B20O0 (since 2013) is applied primarily for BMW 25i vehicles. It reaches 238 hp at 5,000 rpm and 350 NM at 1,250-4,800 rpm.

  3. N20B20M0 (since 2012) is a variation of the engine used for BMW 25i models. Its power is 218 hp at 5,000 rpm and 310 Nm at 1,350-4,800 rpm.
  4. N20B20U0 (since 2011) is a variation of the engine, which has a high compression ratio of 11. BMW 20i models feature N20B20U0 engines. The boost pressure is 8 psi (0.55 bar) thanks to the exhaust system with a smaller calibre. The power of this engine is 184 hp at 5,000 rpm and 270 Nm at 1,250-4,500 rpm.
  5. N20B20U0 (since 2013) is the least powerful variation of the engine, which is used for BMW 18i cars. With the compression ratio of 10, its power is 156 hp at 5,000 rpm and 240 Nm at 1,250-4,400 rpm.

 

Engine Applications

115 kW version:

  • 2013-present BMW E89 Z4 sDrive18i

135 kW version:

  • 2011–present E84 X1 xDrive/sDrive20i
  • 2011–present F25 X3 xDrive20i
  • 2012–2015 F30 320i
  • 2013–present F34 320i GT
  • 2011–present F10 520i
  • 2013-present F10 520Li
  • 2011–present E89 Z4 sDrive20i
  • 2014–present F22 220i
  • 2015-present Brilliance Huasong 7 MPV

160 kW version:

  • 2012–present F20 125i
  • 2013–present F10 525Li
  • 2015-present Brilliance Huasong 7 MPV

170 kW version:

  • 2014–present F22 225i

180 kW version:

  • 2011–present E89 Z4 sDrive28i
  • 2011–2015 E84 X1 xDrive/sDrive28i
  • 2012–present F25 X3 xDrive28i
  • 2011–2016 F30 328i
  • 2011–present F10 528i
  • 2013–2016 F34 328i GT
  • 2014–2016 F22 228i
  • 2014–present F26 X4 xDrive20i

BMW N20 Engine Problems and Reliability

The majority of pluses and minuses of the N20 engine are akin to the 1.6-liter engine from the N13 series. Among the major disadvantages are high vibration, rough idling and high fuel consumption.

  1. High vibration. If you feel that the engine vibrates too much, look at the fuel injectors, which can be dirty. To solve the problem, clean the fuel injectors.
  2. Rough idling. If you want to prevent rough idling, take care that the throttle flap and idling valve are clean. They cause rough idling when they get dirty.
  3. High fuel consumption. When you face this problem, you need to check the airflow meter. As a rule, it’s the main cause of high fuel consumption.
  4. Timing chain. If your timing chain on the N20 engine hasn’t been replaced, then you might want to think about doing it. Timing chain failure could cost a lot more than just the cost of replacing it. As an independent shop, we charge $1500 for replacement and labor, while BMW dealerships would be double that. This is a difficult DIY job as well (if you’re comfortable with cars), but at around $500 in parts and installation, it’s much cheaper for those who know how to do it themselves.
  5. Frequent changes of oils and fuels with different octane numbers have a negative effect on engine efficiency. Therefore, you need to pour only high-quality gasoline (98th) and use the oil recommended by BMW.

On the Web, there are various expert conclusions about a poorly implemented oil supply system. In motors up to 2013, this problem manifests itself in almost 100% of cases when a mileage of 100 thousand km is reached. Somewhere in this period, there is a turn of the liners. It is impossible to determine the problem with the oil supply at the stage of operation – the “disease” is diagnosed after the jam. After 2013 (final restyling), there is no such problem.

With regular and timely maintenance, the N20B20 engine will last a long time, and its problems are mostly related to improper operation or normal wear and tear. Experts recommend at around 100 thousand km. replace timing, VANOS, injectors, caps.

This will allow the engine to “refresh” and drive another 100 thousand km without serious problems. If you are lucky, even with stock components it will be possible to “run” 100 thousand miles without serious breakdowns. Up to 200 thousand km. the engine is unlikely to survive without repair, but even this is an excellent result for a modern internal combustion engine.

Most mechanics agree that buying a pre-2013 BMW N20B20 is not a good idea. There is a high likelihood of a problem with the oil supply on these motors. If its mileage exceeds 100 thousand km, then, probably, the motor has already survived a jam and a major overhaul. On such internal combustion engines, the problem of oil supply has probably been resolved, therefore, in this case, it is better to take BMW N20 engines up to 2013 as refurbished, but their price should also below.

After 2013, cars based on the BMW N20B20 are recommended for purchase. True, in 8-9 years their resource could also be rolled out, so there is a risk of taking a motor that is just beginning to “hurt”. It all depends on the operation of the previous owner.

BMW N20 Engine Tuning

As can be easily understood from the preceding description, in fact, there are only two variations of BMW N20 engines: one with a compression ratio of 10:1 and the other with a compression ratio of 11:1. The range of other motors is provided by the wealth of different settings of the engine control unit.

Structurally, the difference between these engines is only in the form of pistons. For engines with a compression ratio of 11:1 is used with a smaller volume of the piston recess in the piston crown.

Thus, any engine with a compression ratio of 10:1 is possible to boost on 245 hp. This applies to models of BMW z4-1.8i, BMW 125i, BMW-X1 20i and BMW-X3 20i, and some models with the index 20i, which has the engine with low compression (available in countries with poor gasoline, S858 option).

For other models, N20B20-U0 motor to achieve identical factory settings is necessary to change the piston. However, experience has shown that engines with a compression ratio of 11 in the whole work fine on a regular firmware 245 hp.

Last update on 2021-10-26 / Affiliate links / Images from Amazon Product Advertising API

Dan Hoffman

Dan is a co-founder of Engineswork. He knows everything about internal combustion engines. Ask your questions in comments down below this article - he will be glad to help you anytime.

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