Motorad 447-185 Engine Coolant Thermostat - Front

Reliable Engine Coolant Thermostat for Chevrolet, GMC, and Hummer

The Motorad Standard 447-185 engine coolant thermostat is designed to maintain optimal engine temperature for select Chevrolet, GMC, and Hummer models. Engineered with precision, this thermostat ensures efficient coolant flow and temperature regulation to support engine performance and longevity.

• Sealing flange outside diameter: 2.13 inches
• Standard type thermostat with a 185°F start to open temperature
• Includes a rubber O-ring gasket for a secure seal
• Bypass diameter of 1.18 inches and bypass length of 1.36 inches
• Flange thickness of 0.05 inches for proper fitment
• Compatible with Chevrolet Express 2500/3500, GMC Sierra 2500/3500 HD, Hummer H1, and GMC Savana 2500/3500

About the Motorad Standard Product Line

The Motorad Standard line offers dependable engine cooling components designed to meet OEM specifications. This product line focuses on delivering reliable performance and fitment for a range of vehicles, including heavy-duty trucks and SUVs. The 447-185 thermostat from the Standard line provides consistent temperature control with quality sealing materials to prevent leaks and ensure durability.

Product Details and Specifications

This engine coolant thermostat features a start to open temperature of 185 degrees Fahrenheit, which helps regulate the engine’s operating temperature by controlling coolant flow. The included rubber O-ring gasket ensures a tight seal between the thermostat housing and engine block, reducing the risk of coolant leaks. The bypass diameter of 1.18 inches and bypass length of 1.36 inches allow for proper coolant circulation during engine warm-up. The sealing flange outside diameter measures 2.13 inches, and the flange thickness is 0.05 inches, ensuring compatibility with specified vehicle models.

Compatible Vehicles and Applications

• Chevrolet Express 2500 and Express 3500
• GMC Savana 2500 and Savana 3500
• GMC Sierra 2500 HD, Sierra 2500 HD Classic, Sierra 3500, Sierra 3500 Classic, and Sierra 3500 HD
• Chevrolet Silverado 2500 HD, Silverado 2500 HD Classic, Silverado 3500, Silverado 3500 Classic, and Silverado 3500 HD
• Hummer H1

Common Issues Addressed by This Thermostat

• Engine overheating due to thermostat failure
• Coolant leaks caused by worn or damaged seals
• Poor engine temperature regulation affecting performance
• Inconsistent coolant flow during engine warm-up
• Reduced fuel efficiency from improper engine temperature

Installation Notes and Tips

This thermostat does not include an installation tool, so ensure you have the proper tools for removal and installation. Before installing, verify the sealing surface is clean and free of debris to ensure a proper seal with the included rubber O-ring gasket. Follow vehicle-specific service manual instructions for torque specifications and installation procedures. Proper installation helps prevent leaks and ensures accurate temperature control.

Quality Assurance and Warranty

The Motorad Standard 447-185 thermostat is manufactured to meet OEM standards for fit and function. It includes a high-quality rubber gasket to maintain a secure seal and prevent coolant leaks. While specific warranty details are not provided, Motorad products typically adhere to industry quality controls to ensure reliable operation within the specified temperature range of 185°F.