BMW N46

The BMW N46 is a naturally aspirated inline-four 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 engine (which does not have Valvetronic).

In 2007, the N46's successor - the BMW N43 - 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 turbocharged four-cylinder engine.

Design
Compared with its N42 predecessor, the N46 features a revised crankshaft, intake manifold and valvetrain. 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.

N46B18
The N46B18 has a 1796 cc displacement and produces 85 kW and 175 Nm.

Applications:
 * 2004-2005 E46 316i/316ti

N46B20U0
The N46B20U0 produces 105 kW and 200 Nm.


 * 2007-2008 E90 318i

N46B20U1
The N46B20U1 produces 95 kW and 180 Nm.

Applications:
 * 2005-2007 E87 118i
 * 2005-2007 E90/E91 318i

N46B20U2
The N46B20U2 produces 100 kW and 180 Nm. 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 105 kW and 200 Nm.

Applications:
 * 2004-2006 E46 318i, 318Ci and 318ti

N46B20O1
The N46B20O1 produces 110 kW and 200 Nm. 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 Z4 2.0i
 * 2004-2007 E87 120i
 * 2005-2007 E90/E91 320i

N46NB20
The N46B20 produces 127 kW and 210 Nm. 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

N46B20 engine number key code: