[REPLACEMENT OVER BLOW CAP] The radiator cap holds the coolant inside the radiator, it also works as a two-way valve that keeps the right pressure inside so the radiator does it work correctly. Symptoms of a Bad Radiator Cap: air enters the system, low coolant level, coolant leaks, overflowing reservoir, overheating engine. [REPLACES PART] Coolant cap 17137516004 17117639021 [FRIENDLY NOTE] It is extremely important to always make to allow the engine to cool down removing the radiator cap, as removing the cap from a can cause sudden coolant spray and severe . Condition: New Manufacturer Part Number: 17137516004 COMPATABILITY: 2 Series F87 M2 (10/2016 - 12/2019) 3 Series E90 (01/2007 - 07/2008) 3 Series E90 (03/2008 - 10/2011) 3 Series E92 (07/2006 - 02/2010) 3 Series E92 (09/2009 - 06/2013) 3 Series E93 (03/2007 - 02/2010) 3 Series E93 (07/2009 - 10/2013) 3 Series F80 (04/2012 - 06/2015) 3 Series F80 (01/2015 - 10/2018) 4 Series F82 (02/2013 - 02/2017) 4 Series F82 (05/2016 - 12/2019) 4 Series F83 (06/2013 - 02/2017) 4 Series F83 (05/2016 - 12/2019) 5 Series E60 (12/2001 - 12/2009) 5 Series E60 (11/2005 - 12/2009) 5 Series E61 (10/2002 - 02/2007) 5 Series E61 (11/2005 - 05/2010) 5 Series F07 GT (09/2008 - 06/2013) 5 Series F10 (01/2009 - 06/2013) 5 Series F10 (10/2012 - 10/2016) 5 Series F11 (02/2009 - 06/2013) 5 Series G30 (10/2015 - 12/2019) 5 Series F90 M5 (01/2016 - 12/2019) 6 Series E63 (05/2002 - 07/2010) 6 Series E63 (04/2006 - 07/2010) 6 Series E64 (09/2002 - 07/2010) 6 Series E64 (04/2006 - 07/2010) Colour: black Material: plastic Package Contents: 1 * Radiator Cap Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.