Dorman 902-990 Engine Coolant Thermostat Housing - Water Pump

Overview of Dorman Engine Coolant Thermostat Housing 902-990

The Dorman 902-990 engine coolant thermostat housing is designed for reliable cooling system performance in select Audi and Volkswagen vehicles. Constructed from durable black plastic, this thermostat housing ensures proper coolant flow and temperature regulation for models like the Audi A4, A4 Quattro, Passat, and Volkswagen Vanagon.

• Material: High-quality black plastic for corrosion resistance
• Outlet port diameter: 1.5 inches for precise coolant flow
• Includes gasket and O-ring for secure sealing
• Two mounting holes with 0.35-inch diameter for stable installation
• Housing neck angled at 45 degrees from base for optimal fitment
• Package contains water outlet and O-ring; bolts not included
• Compatible with Audi 4000, A4, A4 Quattro, Passat, Quantum, and Volkswagen Vanagon

Detailed Product Description

The Dorman 902-990 thermostat housing is engineered to replace the original equipment part in specific Audi and Volkswagen models. Its black plastic construction offers resistance to corrosion and heat, which is essential for maintaining the integrity of the engine cooling system. The housing features a 1.5-inch outlet port diameter, facilitating efficient coolant flow from the engine to the radiator. Two mounting holes, each with a 0.35-inch diameter, provide secure attachment points, while the 45-degree neck angle ensures proper alignment with the vehicle’s cooling system hoses. This part includes a gasket and O-ring to prevent leaks, although bolts are not included in the package. The thermostat itself is not part of this assembly, allowing for separate replacement if needed.

Compatible Vehicles and Applications

This engine coolant thermostat housing is compatible with a range of Audi and Volkswagen vehicles, including:

• Audi 4000
• Audi A4 and A4 Quattro
• Volkswagen Passat and Quantum
• Volkswagen Vanagon

It is designed to meet the specific fitment requirements of these models, ensuring proper installation and function within the cooling system.

Common Issues Addressed by This Thermostat Housing

• Coolant leaks caused by cracked or damaged thermostat housings
• Overheating due to improper coolant flow
• Corrosion-related failures in original plastic housings
• Loose or damaged mounting points affecting coolant system integrity
• Replacement of worn or missing gaskets and seals

Installation Notes and Tips

When installing the Dorman 902-990 thermostat housing, ensure the engine is cool before beginning work. Use the included gasket and O-ring to create a proper seal and prevent leaks. Verify that the mounting holes align correctly with the vehicle’s mounting points and use appropriate bolts (not included) to secure the housing. Inspect the thermostat separately and replace if necessary, as this housing does not include the thermostat. After installation, refill the cooling system and check for leaks during engine warm-up.

Quality Assurance and Warranty

Dorman parts are manufactured to meet or exceed OEM specifications for fit, form, and function. The 902-990 thermostat housing undergoes quality checks to ensure durability and performance in demanding automotive environments. While specific warranty details may vary, Dorman typically offers limited warranties covering defects in material and workmanship. Consult product documentation for exact warranty terms.