BMW has replaced this cap with part number 17117639020 (click here). This 021 part number may still be available for a limited time.While your BMW cooling system may be considered very reliable, it's all depending on this coolant reservoir cap. This cap is not just to seal the coolant bottle - it regulates and maintains the pressure in the cooling system. A failed cap can lower the pressure inside the system and lead to an overheating situation. Replacement of the cap is recommended every three years to ensure optimum cooling efficiency and performance. It's a simple and inexpensive preventative maintenance step.
BMW Fitments: 3 SeriesE90 / E91 / E92 / E93 (06-13) > M3
3 SeriesF80 (2015-2018) > M3 (2015-2018)
4 SeriesF82 / F83 (2015-2020) > M4 (2015-2020)
5 SeriesE60 / E61 (04-10) > 525i N52 (2006-2007)
E60 / E61 (04-10) > 525xi N52 (2006-2007)
E60 / E61 (04-10) > 528i
E60 / E61 (04-10) > 528xi
E60 / E61 (04-10) > 530i N52 (2006-2007)
E60 / E61 (04-10) > 530xi N52 (2006-2007)
E60 / E61 (04-10) > 535i
E60 / E61 (04-10) > 535xi
E60 / E61 (04-10) > 545i
E60 / E61 (04-10) > 550i
E60 / E61 (04-10) > M5
5 SeriesF10 / F11 (11-16) > 528i N20 (2012-2016)
F10 / F11 (11-16) > 528i N52 (2011)
F10 / F11 (11-16) > 535i
F10 / F11 (11-16) > 535i xDrive
F10 / F11 (11-16) > 550i
F10 / F11 (11-16) > 550i xDrive
F10 / F11 (11-16) > Hybrid 5
6 SeriesE63 / E64 (04-10) > 645Ci
E63 / E64 (04-10) > 650i
E63 / E64 (04-10) > M6
6 SeriesF12 / F13 (12-18) > 640i
F12 / F13 (12-18) > 650i
F12 / F13 (12-18) > 650i xDrive
7 SeriesF01 / F02 (2009-2015) > 740Li
F01 / F02 (2009-2015) > 740i
F01 / F02 (2009-2015) > 750Li
F01 / F02 (2009-2015) > 750Li xDrive
F01 / F02 (2009-2015) > 750i
F01 / F02 (2009-2015) > 760Li
X5 SeriesE70 X5 (07-13) > X5 3.0si
E70 X5 (07-13) > X5 4.8i
E70 X5 (07-13) > X5 M
E70 X5 (07-13) > X5 xDrive50i
X6 SeriesE71 X6 (2008-2014) > X6 M
E71 X6 (2008-2014) > X6 xDrive35i
E71 X6 (2008-2014) > X6 xDrive50i
