Rein CTA0011 Engine Coolant Thermostat Housing Assembly

OE Thermostat Housing Assembly

Rein CTA0011 is an OE quality engine coolant thermostat housing assembly built for direct replacement service on select BMW cooling systems. It is engineered to match original equipment design specifications, with factory-style materials and tolerances for a clean install and consistent cooling performance.

Compatible with BMW 325Ci, 330Ci, X3, X5, 320i, 325i, 325xi, 330i, 330xi, 525i, 530i, Z4, Z3, 323Ci, 323i, 328Ci, 328i, and 528i applications across the listed model years, this Rein thermostat housing assembly is temperature calibrated to 97 degrees Celsius for proper operating temperature control.

• Matches original equipment design specifications
• Direct fitment for easier installation
• Built to strict engineering standards for materials and tolerances
• Thermostat calibrated to 97 degrees Celsius
• OE-style housing construction based on vehicle-specific factory requirements

Detailed Product Overview

The Rein CTA0011 thermostat housing assembly is designed as a direct OE replacement for BMW cooling system service. Rein uses OEM-cast molds to help maintain factory dimensions, which supports accurate fitment and reliable sealing at the housing interface. The assembly is produced with high-quality metal or plastic construction, depending on the vehicle’s original design requirements, and the thermostat is calibrated for a precise response to cooling demand. This part cross-references Genuine 11537509227 and 11530139877 for the same application.

Common Cooling System Issues

• Engine running too cool or too hot due to thermostat control problems
• Coolant leaks at the thermostat housing
• Fitment issues from worn or distorted OE-style housings
• Temperature fluctuation from inconsistent thermostat response
• Cooling system service needs on BMW 325Ci, 330Ci, X3, X5, and related models

Installation Notes

Verify the vehicle application before installation and compare the original housing configuration to the replacement part. Clean the mating surfaces thoroughly, inspect adjacent cooling system components, and follow the manufacturer’s service procedure for coolant refill and bleeding after installation. For BMW 325Ci, 330Ci, X3, X5, and other listed applications, correct sealing and proper coolant system bleeding are important for stable operating temperature.

Quality Assurance

Rein manufactures this thermostat housing assembly to meet or exceed OE material expectations and factory tolerances. The part number CTA0011 is built for dependable service life and consistent temperature control in the specified BMW applications.