Motorad 948-221 Engine Coolant Thermostat Housing Assembly

Integrated Thermostat Housing for OE Fitment

Motorad 948-221 is an integrated engine coolant thermostat housing assembly built for vehicles that require a 221°F opening temperature and OE-style cooling system control. It combines the thermostat, housing, sensor, and seal in a single service part for select Audi applications, including Audi RS5, Audi A8 Quattro, and Audi S5.

The Motorad Integrated Housing Thermostat line is engineered for direct replacement service, with OEM specifications and processes used in manufacturing. This part number, 948-221, uses a copper case and wax compound for quick reaction to coolant temperature changes and stable operation in demanding cooling systems.

Key Features

• Engine coolant thermostat housing assembly with integrated design
• 221°F start-to-open temperature
• Black housing with plastic, stainless steel, and copper construction
• Rubber gasket/seal included
• 5 bolt holes and 2 outlet ports
• Outlet diameters: 1.50 in and 1.00 in
• No bleeder hole and no jiggle pin
• OE supplier manufacturing standards

Detailed Description

Motorad 948-221 is intended for cooling system service where the thermostat and housing are serviced together. The integrated housing design helps restore proper coolant flow control and temperature regulation in Audi RS5, Audi A8 Quattro, and Audi S5 applications that call for a 221°F thermostat specification. This part cross-references Dorman OE Solutions 902-5873 for the same application.

As part of the Motorad Integrated Housing Thermostat product line, this assembly is manufactured to OEM specifications and uses materials selected for thermal response and durability. The copper case and wax compound are used to react quickly to coolant temperature changes, supporting consistent engine operating temperature control.

Vehicle Fitment

• Fits 2013-2016 Audi RS5, N/A; temperature rating of 221F, includes thermostat, housing, sensor, and seal, meets OE specifications.
• Fits 2011 Audi RS5, N/A; temperature rating of 221F, includes thermostat, housing, sensor, and seal, meets OE specifications.
• Fits 2011-2012 Audi A8 Quattro, N/A; temperature rating of 221F, includes thermostat, housing, sensor, and seal, meets OE specifications.
• Fits 2008-2012 Audi S5, N/A; temperature rating of 221F, includes thermostat, housing, sensor, and seal, meets OE specifications.

What It Helps Fix

• Engine running too cool or too hot due to thermostat control issues
• Coolant temperature instability during normal driving
• Leaking thermostat housing seal or degraded rubber seal
• Service needs on integrated thermostat and housing assemblies
• Cooling system faults tied to worn thermostat response

Installation Notes and Tips

Verify the 221°F temperature specification, 5-bolt housing pattern, and 2-port outlet layout before installation. Replace the sealing surface carefully and confirm the rubber gasket is seated correctly. Because this assembly does not include bolts or mounting hardware, reuse or source the correct fasteners separately as required by the vehicle service procedure.

Quality Assurance

Motorad manufactures this thermostat housing assembly with OEM-quality materials and OE supplier standards. It is built to meet OEM specifications and processes for service in demanding automotive cooling systems.