The BMW N46 is a naturally aspirated

inline-four A straight-four engine (also called an inline-four) is a four-cylinder piston engine where cylinders are arranged in a line along a common crankshaft. The vast majority of automotive four-cylinder engines use a straight-four layout (with the e ...

piston engines which replaced the BMW N42 and was produced from 2004 to 2015. The N46 serves as the basis for the smaller

BMW N45 The BMW N45 is a naturally aspirated four-cylinder petrol engine which replaced the BMW N40 and was produced from 2004-2011. It was produced alongside the BMW N46 engine and only sold in several countries, where vehicle taxes favoured small-displ ...

engine (which does not have Valvetronic). In 2007, the N46's successor - the

BMW N43 The BMW N43 is a naturally aspirated four-cylinder petrol engine which was sold from 2006-2013. It replaced both the BMW N46 and BMW N45 engines. However the N43 was not sold in countries with high sulfur fuel, therefore the N45/N46 engines rema ...

- was introduced. However, the direct-injected N43 was not sold in countries with high-sulfur fuel, so the N46 continued to be produced alongside the N43. The N46 continued production until 2015, when the last N46 models were replaced by the

BMW N13 Prince is the codename for a family of straight-four 16-valve all-aluminium gasoline engines with variable valve lift and variable valve timing developed by PSA Peugeot Citroën and BMW. It is a compact engine family of 1.4–1.6 L in disp ...

turbocharged four-cylinder engine.

Design

Compared with its N42 predecessor, the N46 features a revised crankshaft,

intake manifold In automotive engineering, an inlet manifold or intake manifold (in American English) is the part of an engine that supplies the fuel/ air mixture to the cylinders. The word ''manifold'' comes from the Old English word ''manigfeald'' (from the ...

and

valvetrain A valvetrain or valve train is a mechanical system that controls the operation of the intake and exhaust valves in an internal combustion engine. The intake valves control the flow of air/fuel mixture (or air alone for direct-injected engines) ...

. In 2007, the N46 was updated, which was known as the N46N. Changes included the intake manifold, exhaust camshaft and the engine control unit was changed from Bosch Motronic version ME9.2 to version MV17.4.6. The redline is 6,500 rpm.

Versions

N46B18

The N46B18 has a displacement and produces and . Applications: * 2004-2005 E46 316i/316ti

N46B20U0

The N46B20U0 produces and . * 2007-2008 E90 318i

N46B20U1

The N46B20U1 produces and . Applications: * 2005-2007 E87 118i * 2005-2007 E90/E91 318i

N46B20U2

The N46B20U2 produces and . It was used instead of the N43 engine in countries with high-sulfur fuel. Applications: * 2007-2011 E81/E87 118i * 2007-2013 E90 318i

N46B20A

The N46B20A produces and . Applications: * 2004-2006 E46 318i, 318Ci and 318ti

N46B20O1

The N46B20O1 produces and . On models with secondary air injection, peak torque occurs at 3750 rpm instead of 3600 rpm. Applications: * 2004-2007 E83 X3 2.0i * 2005-2008

E85 E85 is an abbreviation typically referring to an ethanol fuel blend of 85% ethanol fuel and 15% gasoline or other hydrocarbon by volume. In the United States, the exact ratio of fuel ethanol to hydrocarbon may vary according to ASTM 5798 that ...

Z4 2.0i * 2004-2007 E87 120i * 2005-2007 E90/E91 320i

N46NB20

The N46B20 produces and . It was used instead of the N43 engine in countries with high-sulfur fuel. Applications: * 2007-2011 E81/E82/E87/E88 120i * 2007-2013 E90/E91/E92/E93 320i * 2007-2010 E60 520i * 2009-2015 E84 X1 sDrive18i / xDrive18i * 2007-2010 E83 X3 2.0i

References

{{DEFAULTSORT:Bmw N46 N46 Straight-four engines Gasoline engines by model