Dorman 902-5056 Engine Coolant Thermostat Housing

Engine Coolant Thermostat Housing for Mitsubishi Diamante

Dorman 902-5056 is a replacement engine coolant thermostat housing built for specified Mitsubishi Diamante applications from 1997-2004. It matches the stock housing’s fit and durability requirements and is made to handle repeated temperature swings in the cooling system.

• Direct replacement engine coolant thermostat housing
• Fits 1997-2004 Mitsubishi Diamante, cooling system thermostat housing application
• Metal construction with a natural finish
• Outlet port diameter: 1.313 in.
• Three mounting holes with 0.313 in. mounting hole diameter
• Gasket included; thermostat not included
• Housing neck angle: 180 degrees
• No air vent (bleeder valve); O-rings not required

Detailed Fitment and Design

Built for the cooling system on Mitsubishi Diamante models, this Dorman thermostat housing is engineered to replace the original housing with the correct shape, port size, and mounting layout. The metal body is designed for durability in high-heat, high-cooldown cycles, helping maintain a secure seal at the thermostat housing location. Dorman 902-5056 is a practical choice when servicing a leaking, cracked, or corroded thermostat housing on a 1997-2004 Mitsubishi Diamante.

This part cross-references Four Seasons 85271 for the same application.

What It Helps Address

• Coolant leaks at the thermostat housing
• Cracked or warped original housing
• Corrosion around the coolant outlet
• Improper sealing at the thermostat housing gasket surface
• Cooling system service on a Mitsubishi Diamante

Installation Notes and Tips

Transfer the thermostat from the original assembly if needed, since the thermostat is not included. Inspect the mating surface, replace worn coolant hoses or clamps as needed, and confirm the gasket seats evenly before refilling and bleeding the cooling system. Verify the outlet port diameter and mounting pattern against the original housing before installation.

Quality Assurance

Dorman designs this replacement housing to match the fit and durability of the stock part and to withstand extreme temperature changes for extended service life. Part number 902-5056 is built as a direct-fit cooling system replacement for specified Mitsubishi Diamante vehicles.