The N55 engine uses 2 deflection rollers in the serpentine belt system. This pulley is the smaller of the 2, measuring 75mm (2.95") in diameter.
This part is listed by BMW as BMW part number 11287578674 (11-28-7-578-674) and is described as INA OEM Deflection Pulley (75mm) for Serpentine Belt on N55 engine. Fits E82/E88 135i, 135is (2011, 2012, 2013), E90/E92/E93 335i, 335i xDrive (2011, 2012, 2013), E84 X1 35i xDrive (2013, 2014, 2015).
For full BMW fitment information or for assistance from one of our BMW experts, we recommend calling us at 877-639-9648.
BMW Fitments:
1 Series
E82 / E88 (08-13) > 135i N55 (11-13)
E82 / E88 (08-13) > 135is N55 (11-13)
3 Series
E90 / E91 / E92 / E93 (06-13) > 335i N55 (11-13)
E90 / E91 / E92 / E93 (06-13) > 335xi N55 (11-13)
X1 Series
E84 X1 (2013-2015) > X1 35i xDrive