Motorad 1001-221 Engine Coolant Thermostat Housing Assembly

Integrated Thermostat Housing for Volkswagen Cooling Systems

The Motorad 1001-221 integrated housing thermostat is built for precise coolant temperature control in demanding engine cooling systems. It is a direct-fit engine coolant thermostat housing assembly for 2004-2006 Volkswagen Phaeton applications and includes the thermostat housing, sensor, and seal noted in the fitment data.

Motorad’s Integrated Housing Thermostat line focuses on OE-style replacement parts that combine the thermostat and housing into one serviceable assembly. This design supports cleaner replacement on the Volkswagen Phaeton cooling system while maintaining the 221°F opening temperature specified for this application.

• Part number: 1001-221
• Fits 2004-2006 Volkswagen Phaeton
• Integrated engine coolant thermostat housing assembly
• 221°F start-to-open temperature
• Bleeder hole and jiggle pin included for air management
• Rubber gasket/seal included
• 7 bolt holes for OE-style mounting
• 3 outlet ports with diameters of 0.63 in, 1.32 in, and 1.51 in
• Constructed with aluminum, stainless steel, and copper materials

Detailed Product Overview

The Motorad 1001-221 thermostat housing assembly is manufactured to OE specifications and processes using OEM-quality materials. Its copper case and wax compound are engineered for fast reaction to coolant temperature changes, helping the thermostat regulate engine operating temperature with consistent response. For Volkswagen Phaeton cooling system service, this integrated housing format reduces the need to source separate thermostat and housing components.

This part cross-references Monroe Shocks & Struts 34797 for the same application. The Motorad 1001-221 also cross-references Wix 51010 for the same application.

What This Part Helps Address

• Engine running too cool or too hot due to thermostat control issues
• Coolant leaks at the thermostat housing or seal interface
• Air trapped in the cooling system after service
• Slow thermostat response affecting temperature regulation
• Service replacement needs on 2004-2006 Volkswagen Phaeton cooling systems

Installation Notes and Tips

Verify the 221°F temperature rating, 7-bolt-hole layout, and 3 outlet port sizes before installation. Replace the housing seal during service, and inspect mating surfaces for corrosion or debris so the rubber seal seats correctly. Use the bleeder hole and jiggle pin during filling and bleeding to help purge trapped air from the cooling system. Confirm connector and sensor alignment against the original Volkswagen Phaeton thermostat housing assembly before final assembly.

Quality Assurance

Motorad manufactures this integrated housing thermostat with OEM-quality materials and OE-supplier standards. The part is built to meet OEM specifications for the 2004-2006 Volkswagen Phaeton application and to withstand demanding automotive cooling system conditions.