Dorman 902-778 Engine Coolant Thermostat Housing - Inner

Overview of Dorman Engine Coolant Thermostat Housing 902-778

The Dorman 902-778 engine coolant thermostat housing is designed to provide reliable cooling system performance for select Ford, Lincoln, Mazda, and Mercury vehicles. Constructed from durable black plastic, this thermostat housing includes a gasket for a secure seal and is engineered to meet OEM specifications.

• Material: High-quality black plastic for corrosion resistance
• Includes gasket for proper sealing
• Outlet port diameter: 1.5 inches
• Mounting holes: 3 with 0.188 inch diameter each
• Housing neck angle: 90 degrees for precise fitment
• Compatible with Ford Escape, Fusion, Mariner, Lincoln Milan, Mazda MPV, Mercury Tribute, and Zephyr
• Part number: 902-778

Detailed Product Description

This engine coolant thermostat housing by Dorman is engineered to replace the original housing on various Ford, Lincoln, Mazda, and Mercury models. The black plastic construction offers resistance to corrosion and heat, ensuring long-lasting performance. The housing features a 90-degree neck angle and a 1.5-inch outlet port diameter, designed to match the exact specifications of the original part. It includes three mounting holes with a diameter of 0.188 inches each, allowing for secure installation. The package contains the thermostat housing and a gasket, but does not include the thermostat, bolts, or O-rings.

Compatible Vehicles and Applications

This thermostat housing is compatible with the following makes and models:

• Ford Escape and Fusion
• Lincoln Mariner and Milan
• Mazda MPV
• Mercury Tribute and Zephyr

Use this part number 902-778 when searching for a replacement thermostat housing for these vehicles to ensure proper fit and function.

Common Issues Addressed by This Thermostat Housing

• Coolant leaks caused by cracked or damaged housing
• Overheating due to faulty thermostat housing seal
• Corrosion and wear from prolonged exposure to coolant and heat
• Improper coolant flow from warped or broken housing
• Replacement of worn or broken mounting points

Installation Notes and Tips

• Ensure the engine is cool before beginning installation to avoid burns
• Remove old gasket residue thoroughly to prevent leaks
• Use the included gasket for a proper seal; bolts are not included and must be reused or replaced separately
• Verify the 90-degree neck angle aligns with your vehicle’s coolant hose
• Check mounting hole alignment and torque bolts to manufacturer specifications

Quality Assurance and Warranty

Dorman manufactures this thermostat housing to meet or exceed OEM standards for fit, form, and function. The plastic material is selected for durability and resistance to corrosion. This part is backed by Dorman’s limited warranty, providing coverage against defects in material and workmanship under normal use.