Dorman 902-5025 Engine Coolant Thermostat Housing

Overview of Dorman Engine Coolant Thermostat Housing 902-5025

The Dorman 902-5025 engine coolant thermostat housing is designed for select BMW models, including the 530i, 540i, 740i, 740iL, and 840Ci. This thermostat housing is constructed from durable plastic with a natural color finish, engineered to provide reliable coolant flow management in your vehicle's engine cooling system.

• Material: High-quality plastic for corrosion resistance
• Color: Natural finish
• Outlet port diameter: 1.5 inches
• Mounting holes: 4 holes with 0.313 inch diameter each
• Housing neck angle: 90 degrees for precise fitment
• Includes thermostat housing with gasket (thermostat and bolts not included)
• No air vent (bleeder valve) or O-rings required

Detailed Product Description

The Dorman 902-5025 thermostat housing is specifically engineered to meet the cooling system requirements of BMW 530i, 540i, 740i, 740iL, and 840Ci models. Made from durable plastic, this housing resists corrosion and withstands the thermal stresses of engine operation. The natural color finish allows for easy inspection during maintenance. The 1.5-inch outlet port diameter and 90-degree housing neck angle ensure proper coolant flow and compatibility with factory cooling system components. Four mounting holes with a diameter of 0.313 inches provide secure attachment to the engine block. This part comes with a gasket included to ensure a tight seal, although the thermostat and mounting bolts are not included.

Common Applications and Issues Addressed

• Replacement for cracked or leaking thermostat housing
• Prevents coolant leaks that can cause engine overheating
• Restores proper coolant flow in BMW 530i, 540i, 740i, 740iL, and 840Ci models
• Addresses coolant system failures due to housing warping or damage
• Helps maintain engine temperature regulation by housing the thermostat securely

Installation Notes and Tips

When installing the Dorman 902-5025 thermostat housing, ensure the engine is cool before beginning work. Remove the old housing carefully to avoid damaging surrounding components. Clean the mounting surface thoroughly to ensure a proper seal with the included gasket. Since bolts and thermostat are not included, reuse the original hardware or source replacements as needed. Tighten mounting bolts evenly to the manufacturer’s torque specifications to prevent leaks. Verify coolant levels and check for leaks after installation.

Quality Assurance and Warranty

Dorman parts are manufactured to meet or exceed OEM specifications for fit, form, and function. The 902-5025 thermostat housing undergoes quality control testing to ensure durability and performance in demanding engine environments. While specific warranty details may vary, Dorman typically offers limited warranties covering defects in material and workmanship. Consult product documentation or the supplier for exact warranty terms.