Rein CPE0030P Engine Coolant Reservoir Cap - Radiator

OE Quality Expansion Tank Cap

The Rein CPE0030P engine coolant reservoir cap is a direct replacement for the original expansion tank cap used on a wide range of BMW and Rolls-Royce applications. Built to match OE materials and pressure requirements, it helps maintain proper cooling system pressure for reliable operation.

For BMW 650i, M5, 750i, X5, and other listed applications, this Rein expansion tank cap is designed for direct fitment and consistent sealing performance. The CPE0030P is produced by an original equipment supplier and manufactured to strict engineering standards.

Key Features

• Direct-fit replacement for the OE expansion tank cap
• Manufactured to strict engineering standards for materials and tolerances
• Meets or exceeds OE pressure specifications
• Produced by an original equipment supplier
• Black finish

Detailed Product Information

Rein OE Quality expansion tank caps are built as direct replacements for factory caps on BMW and Rolls-Royce cooling systems. The cap helps keep the coolant system at the proper pressure, which is critical for stable operating temperatures and dependable sealing at the reservoir. Part number CPE0030P is a practical OE-style service part for vehicles that require an exact-fit coolant reservoir cap.

This part cross-references BMW OE numbers 17110152374 and 17111712492 for the same application.

Common Cooling System Issues Addressed

• Loss of coolant system pressure from a worn or weak cap
• Coolant seepage around the expansion tank cap seal
• Pressure-related cooling system warning conditions
• Improper cap fit on BMW and Rolls-Royce expansion tanks
• Replacement of a cracked, aged, or heat-damaged reservoir cap

Installation Notes and Tips

Verify the cap style and pressure specification against the original part before installation. Inspect the expansion tank neck and sealing surface for cracks, debris, or hardened residue, then install the cap on a cool engine to avoid pressure-related injury. Confirm proper seating after installation.

Compatible With 2013-2019 BMW 650i Gran Coupe, Radiator; 2013-2019 BMW 650i xDrive Gran Coupe, Radiator; 2014-2019 BMW M6 Gran Coupe, Radiator; 2013-2018 BMW 650i, Radiator; 2013-2018 BMW 650i xDrive, Radiator; 2012-2018 BMW M6, Radiator; 2004-2018 Rolls-Royce Phantom, N/A; 2013-2017 BMW 550i GT xDrive, Radiator; 2014-2016 BMW 550i, N/A; 2014-2016 BMW 550i xDrive, N/A; 2012-2016 BMW M5, Radiator; 2013-2015 BMW 550i GT, Radiator; 2013-2015 BMW 750i, Radiator; 2013-2015 BMW 750i xDrive, Radiator; 2013-2015 BMW 750Li, Radiator; 2013-2015 BMW 750Li xDrive, Radiator; 2004-2010 BMW X3, N/A; 2006-2008 BMW 750i, N/A; 2006-2008 BMW 750Li, N/A; 2003-2008 BMW 760Li, N/A; 2003-2008 BMW Z4, N/A; 2001-2006 BMW 325Ci, N/A; 2001-2006 BMW 330Ci, N/A; 2004-2006 BMW 760i, N/A; 2001-2006 BMW M3, N/A; 1994-1999 BMW M3, N/A; 2000-2006 BMW X5, N/A; 2001-2005 BMW 320i, N/A; 1992-1995 BMW 320i, N/A; 2001-2005 BMW 325i, N/A; 1992-1995 BMW 325i, N/A; 2001-2005 BMW 325xi, N/A; 2001-2005 BMW 330i, N/A; 2001-2005 BMW 330xi, N/A; 2002-2005 BMW 745i, N/A; 2002-2005 BMW 745Li, N/A; 2001-2003 BMW 525i, N/A; 1991-1995 BMW 525i, N/A; 2001-2003 BMW 530i, N/A; 1994-1995 BMW 530i, N/A; 1997-2003 BMW 540i, N/A; 1994-1995 BMW 540i, N/A; 2000-2003 BMW M5, N/A; 1991-1993 BMW M5, N/A; 2000-2003 BMW Z8, N/A; 1996-2002 BMW Z3, N/A; 1997-2001 BMW 740i, N/A; 1993-1995 BMW 740i, N/A; 1993-2001 BMW 740iL, N/A; 1988-2001 BMW 750iL, N/A; 2000 BMW 323Ci, N/A; 1998-2000 BMW 323i, N/A; 2000 BMW 328Ci, N/A; 1996-2000 BMW 328i, N/A; 1997-2000 BMW 528i, N/A; 1991-1999 BMW 318i, N/A; 1991-1999 BMW 318is, N/A; 1995-1999 BMW 318ti, N/A; 1998-1999 BMW 323is, N/A; 1996-1999 BMW 328is, N/A; 1994-1997 BMW 840Ci, N/A; 1993-1997 BMW 850Ci, N/A; 1992-1995 BMW 325is, N/A; 1994-1995 BMW 850CSi, N/A; 1993 BMW 525iT, N/A; 1989-1993 BMW 535i, N/A; 1987-1992 BMW 735i, N/A; 1988-1992 BMW 735iL, N/A; 1991-1992 BMW 850i, N/A.

Quality Assurance

Rein Automotive OE Quality expansion tank caps are produced to match or exceed OE material and pressure requirements, with direct-replacement fitment for the listed BMW and Rolls-Royce applications. Part number CPE0030P is built for long service life under normal cooling system conditions.