Motorad 405-174 Engine Coolant Thermostat

Motorad 405-174 Engine Coolant Thermostat

The Motorad 405-174 is a standard engine coolant thermostat built to OE specifications for precise temperature control. With a 174°F start-to-open rating, it is suited for BMW cooling systems that require consistent coolant flow management and stable operating temperature.

Key Features

• 174°F start-to-open temperature for OE-specified cooling performance
• Copper case and wax compound for quick response to coolant temperature changes
• Offset design for proper fitment in the intended housing application
• Air relief valve included where applicable to help purge trapped air during service
• Manufactured to OEM quality materials and safety standards by an OE supplier
• Motorad Standard line replacement thermostat, part number 405-174

Product Details

Motorad Standard part number 405-174 is an engine coolant thermostat engineered for direct replacement use in select BMW applications. It is manufactured using OEM specifications and processes, with a copper case and wax compound that react quickly to coolant temperature changes. The thermostat’s 174°F calibration supports the factory cooling strategy in vehicles such as the BMW M3, BMW Z3, and BMW Z4. This part cross-references Eastern Catalytic 50574 for the same application.

Vehicle Fitment

• Fits 2006-2009 BMW Z4, N/A; 174F Temperature thermostat OE Specified Engine Coolant Thermostat.; Standard
• Fits 2001-2006 BMW M3, N/A; 174F Temperature thermostat OE Specified Engine Coolant Thermostat.; Standard
• Fits 2001-2002 BMW Z3, N/A; 174F Temperature thermostat OE Specified Engine Coolant Thermostat.; Standard

Common Issues This Part Can Address

• Engine running too cool or too warm due to thermostat wear
• Delayed coolant circulation after cold start
• Temperature fluctuation from a thermostat that no longer opens at the correct point
• Cooling system service on BMW M3, Z3, or Z4 models with OE-specified 174°F thermostat requirements
• Replacement of a thermostat with degraded wax element or internal response

Installation Notes

Verify the thermostat temperature rating and housing configuration before installation. Inspect the sealing surfaces and replace any worn housing components as needed, since this thermostat is listed without a gasket or seal included. Confirm proper coolant fill and bleed the system carefully after service to remove trapped air.

Quality Assurance

Motorad manufactures this thermostat with OEM-quality materials and safety standards as an OE supplier. It is built to meet OEM specifications for demanding automotive cooling systems and is intended to deliver consistent temperature control in the specified BMW applications. Part number 405-174 is part of Motorad’s Standard line.