Coolant Expansion Tank Cap, OEM - E36, E46, E39, E38, X3, X5, Z3, Z4

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 expansion tank - it regulates and maintains the pressure in the cooling system (2.0 bar). 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 has had many different part numbers for this radiator cap over the years. This part number replaces BMW numbers 17117639022, 17111742231, 17111712669, 17111712492, and 17110152374.

This is an OEM expansion tank cap manufactured by Behr - an original supplier to BMW for many cooling system components. As an OEM it meets all of BMW's original design, fitment, and performance requirements and is TUV approved. OEM parts are the best alternative to more expensive Original BMW parts because they are virtually identical without the inflated price tag. This part has a two year warranty.

BMW Fitments:

3 Series
E30 (84-91) > 318i
E30 (84-91) > 318is
3 Series
E36 (92-99) > 318i M42
E36 (92-99) > 318i M44
E36 (92-99) > 318ic M42
E36 (92-99) > 318ic M44
E36 (92-99) > 318is M42
E36 (92-99) > 318is M44
3 Series
E36/5 (95-99) > 318ti M42
E36/5 (95-99) > 318ti M44
3 Series
E46 (99-05) > 320i
E46 (99-05) > 323Ci
E46 (99-05) > 323i
E46 (99-05) > 325Ci
E46 (99-05) > 325i
E46 (99-05) > 325xi
E46 (99-05) > 328Ci
E46 (99-05) > 328i
E46 (99-05) > 330Ci
E46 (99-05) > 330i
E46 (99-05) > 330xi
E46 (99-05) > M3
5 Series
E34 (89-95) > 525i M50
E34 (89-95) > 530i
E34 (89-95) > 535i
E34 (89-95) > 540i
E34 (89-95) > M5 (91-95)
5 Series
E39 (97-03) > 525i
E39 (97-03) > 528i 97-98
E39 (97-03) > 528i 99-00
E39 (97-03) > 530i
E39 (97-03) > 540i
E39 (97-03) > M5 (00-03)
5 Series
F10 / F11 (11-16) > 550i
F10 / F11 (11-16) > 550i xDrive
F10 / F11 (11-16) > M5 (2013-2016)
6 Series
F12 / F13 (12-18) > 650i
F12 / F13 (12-18) > 650i xDrive
F12 / F13 (12-18) > M6
7 Series
E32 (88-94) > 735i
E32 (88-94) > 735iL
E32 (88-94) > 740i
E32 (88-94) > 740iL
E32 (88-94) > 750iL
7 Series
E38 (95-01) > 740i
E38 (95-01) > 740iL
E38 (95-01) > 750iL
7 Series
E65 / E66 (02-08) > 745Li
E65 / E66 (02-08) > 745i
E65 / E66 (02-08) > 750Li
E65 / E66 (02-08) > 750i
E65 / E66 (02-08) > 760Li
7 Series
F01 / F02 (2009-2015) > 750Li
F01 / F02 (2009-2015) > 750Li xDrive
F01 / F02 (2009-2015) > 750i
8 Series
E31 (91-97) > 840Ci
E31 (91-97) > 850CSi
E31 (91-97) > 850Ci
X3 Series
E83 X3 (04-10) > X3 2.5i M54 (2003-2005)
E83 X3 (04-10) > X3 3.0i M54 (2003-2006)
E83 X3 (04-10) > X3 3.0si N52 (2007-2010)
X5 Series
E53 X5 (00-06) > X5 3.0i M54
E53 X5 (00-06) > X5 4.4i M62 4.4L (99-03)
E53 X5 (00-06) > X5 4.4i N62
E53 X5 (00-06) > X5 4.6is M62
E53 X5 (00-06) > X5 4.8is N62
Z Series
E36/7 / E36/8 Z3 (96-02) > Z3 1.9
E36/7 / E36/8 Z3 (96-02) > Z3 2.3
E36/7 / E36/8 Z3 (96-02) > Z3 2.5
E36/7 / E36/8 Z3 (96-02) > Z3 2.8 97-98
E36/7 / E36/8 Z3 (96-02) > Z3 2.8 99-00
E36/7 / E36/8 Z3 (96-02) > Z3 3.0
E36/7 / E36/8 Z3 (96-02) > Z3 M - S52
E36/7 / E36/8 Z3 (96-02) > Z3 M - S54
Z Series
E52 Z8 (00-03) > Z8 Roadster (2000-2003)
Z Series
E85 / E86 Z4 (03-08) > Z4 2.5i M54
E85 / E86 Z4 (03-08) > Z4 3.0i M54
E85 / E86 Z4 (03-08) > Z4 3.0i N52
E85 / E86 Z4 (03-08) > Z4 3.0si N52
E85 / E86 Z4 (03-08) > Z4 M