Rein EPT0012 Engine Coolant Reservoir

OE Quality Expansion Tank for BMW Cooling Systems

Rein EPT0012 is an OE-quality engine coolant reservoir built for BMW cooling system service. It is made from virgin plastic to help resist heat-cycle cracking and maintain long-term durability in daily driving conditions.

Compatible with BMW 318i, 318is, 318ti, Z3, 525i, and 525iT applications across the listed model years, this Rein expansion tank is engineered for direct fitment and consistent cooling system performance.

• Produced from virgin plastic that meets or exceeds OE material expectations
• Resists cracking and wear caused by repeated heat cycles
• Direct-fit design supports straightforward installation
• Built to strict engineering standards for material quality and dimensional accuracy
• OE-quality replacement for BMW cooling system repair

Detailed Product Overview

The Rein EPT0012 expansion tank is designed to replace a worn or damaged coolant reservoir with a part that matches the original fit and function. Rein manufactures these tanks from virgin plastic with no regrind, helping reduce the risk of premature cracking and coolant loss. For BMW owners servicing older cooling systems, this reservoir supports reliable coolant storage and stable system operation.

This part cross-references URO 17111712835 for the same application. Rein EPT0012 is a practical choice for BMW 318i, 318is, 318ti, Z3, 525i, and 525iT cooling system repairs where OE-style fit and material durability matter.

Common Problems This Part Helps Address

• Coolant leaks from a cracked expansion tank
• Reservoir damage caused by repeated engine heat cycles
• Loss of coolant from aging plastic components
• Poor fitment from worn or incorrect replacement tanks
• Cooling system service needs on high-mileage BMW vehicles

Installation Notes and Tips

Inspect the cooling system before installation and replace any damaged hoses, clamps, or seals as needed. Confirm the reservoir matches the vehicle’s original configuration before installation, and bleed the cooling system carefully after service to remove trapped air.

Fits 1991-1999 BMW 318i, N/A. Fits 1991-1999 BMW 318is, N/A. Fits 1995-1999 BMW 318ti, N/A. Fits 1996-1998 BMW Z3, N/A. Fits 1989-1995 BMW 525i, N/A. Fits 1993 BMW 525iT, N/A.

Quality Assurance

Rein designs OE-quality expansion tanks to meet strict material and tolerance standards. The use of virgin plastic supports durability and helps the reservoir withstand repeated thermal cycling in BMW cooling systems.