BMW N52

Compared with its M54 predecessor, the N52 features Valvetronic (variable valve lift), a lighter block due to the use of a magnesium alloy and an electric water pump (replacing the belt-driven water pump) and a variable output oil pump. The redline was increased from 6,500 rpm to 7,000 rpm, except for N52B25 (130 kW). The N52 engine block is made from a combination of magnesium and aluminium. Magnesium is lighter than aluminium, however it has a greater risk of corrosion from water and may creep under load at high temperatures; this makes traditional magnesium alloys not suited for withstanding the high loads to which an engine block is exposed. Therefore, BMW used a magnesium alloy for the crankcase shell, with an aluminum 'inner block' to overcome the limitations of magnesium alloys. The cylinder liners are made of Alusil. The N52 debuted with solid cast intake and exhaust camshafts, but during production hollow "hydro-formed" camshafts were phased in to reduce weight. Some engines came from the factory equipped with one solid and one hollow camshaft as the solid shaft was being phased out. Engine performance is not affected by installation of mixed camshafts. The engine control unit (also called "DME") varies between model years, generally before 2007 the MSV70 was used and onward the MSV80 was used. For specifically the N51 engine the MSV80.1 was used. ==Models==

N52B25 Applications: • 2006 E90 323i — Canada, Australia and Japan • 2004-2007 E60/E61 523i • 2006-2008 E85 Z4 2.5i Applications: • 2007-2011 E90 323i — Canada, Australia and Japan • 2010-2011 F10 523i • 2009-2011 E89 Z4 sDrive23i Applications: • 2005-2010 E83 X3 2.5si, xDrive25i • 2005-2010 E60/E61 525i, 525xi — except U.S. and Canada • 2004-2013 E90/E91/E92/E93 325i, 325xi — except U.S. and Canada • 2005-2008 E85 Z4 2.5si N52B30 The models of the N52 have a bore of , a stroke of and a compression ratio of 10.7:1. Variations in power output are often due to different intake manifolds and variations of engine management software. Applications: • 2006-2007 E90/E92/E93 325i, 325xi — U.S. and Canada only • 2006-2007 E60/E61 525i, 525xi — U.S. and Canada only • 2006-2008 E85 Z4 3.0i — U.S. and Canada only • 2008-2011 E82/E88 125i • 2008-2010 E60/E61 528i, 528xi — U.S. and Canada only • 2009-2010 E84 X1 xDrive25i Applications: • 2007-2013 E90/E91/E92/E93 328i, 328xi — U.S. and Canada only • 2008-2013 E82/E88 128i — U.S. and Canada only Applications: • 2010-2011 F10 528i Applications: • 2004-2007 E63/E64 630i • 2005-2007 E90/E92/E93 330i, 330xi • 2005-2008 E65/E66 730i • 2005-2009 E60/E61 530i, 530xi • 2009-2015 F01 730i • 2008-2011 E89 Z4 sDrive30i • 2009-2011 E84 X1 xDrive28i • 2009-2012 E87 130i • 2010-2011 F25 X3 28i Applications: • 2005-2008 E85/E86 Z4 3.0si • 2006-2009 E87 130i Applications: • 2006–2010 E83 X3 3.0si • 2006-2010 E70 X5 3.0si, xDrive30i • 2007-2010 E63/E64 630i N51B30 The N51 engine is a SULEV version of the N52 that was sold in parts of the United States that had SULEV legislation. Differences to the N52 versions include a variable-length intake manifold ("DISA") with three stages instead of one, and the static compression ratio lowered from 10.7:1 to 10.0:1. Additionally, the N51 features a secondary air pump ("SAP") not present in the ULEV N52. == Recalls ==

• In 2017, BMW recalled 740,000 six-cylinder models due to reports of the heater for the crankcase ventilation valve short-circuiting and causing a fire. • In 2023, 155,627 vehicles were issued a recall for VANOS bolts that could loosen or break over time. ==See also==