Coolant Return Pipe – BMW 3-Series 5-Series Z3 Z4 (11537502525)

This high-quality TOPRAN coolant pipe (engine side water pipe) is a direct replacement for Genuine Part Number Reference: 11537502525. It also cross-references to genuine BMW number 11531705220. This plastic pipe connects the coolant return hose to the engine block, tucked against the side of the engine under the intake manifold. The plastic is known to become brittle and crack with age, which is a common cause of coolant leaks and low coolant warnings on these models.

Key Features:

Direct replacement for OEM part number 11537502525
Manufactured to meet or exceed OEM specifications
Durable plastic construction
Factory-style fit and function
Also known as coolant bypass pipe, water pipe, coolant return pipe, engine coolant pipe

Compatible With:

BMW 3-Series (E46) – 1998 to 2006
BMW 5-Series (E39) – 1995 to 2003
BMW Z3 – 1995 to 2002
BMW Z4 (E85) – 2002 to 2008
323i, 323Ci, 325i, 325Ci, 328i, 328Ci, 330i, 330Ci, 525i, 528i, 530i, Z3 2.3, Z3 2.5i, Z3 2.8, Z3 3.0i, Z4 2.5i, Z4 3.0i

Engine Codes:
M52B25, M52B28, M54B22, M54B25, M54B30

Year Range:
1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008

This is an aftermarket replacement part, not a genuine BMW component.