Dorman 902-5212 Engine Coolant Thermostat Housing Assembly

Overview

Dorman 902-5212 is an engine coolant thermostat housing assembly built to match the stock housing on specified applications. It combines the housing and thermostat in one replacement assembly and is made to handle repeated temperature swings in the cooling system.

Compatible With Lexus RX450h, Lexus RX450hL, Lexus TX550h+, and Toyota Highlander applications, this thermostat housing assembly supports proper coolant routing and temperature control. The Dorman 902-5212 is a direct-fit replacement for vehicles that use an integrated cover design.

Key Features

• Plastic housing with a black finish for OE-style replacement.
• Includes a gasket seal for proper sealing at the mounting surface.
• Thermostat included with a 189-degree opening temperature.
• Four mounting holes and two outlet ports for the specified cooling system layout.
• Engineered to match stock fit and durability requirements.

Detailed Description

This engine coolant thermostat housing assembly is intended for cooling-system service where the original housing has cracked, warped, or begun leaking. The housing is molded from plastic and uses a gasket-style seal to help maintain a secure connection under heat cycling. With the thermostat included, the assembly is ready for applications that require the integrated housing and cover configuration found on Lexus RX450h, Lexus RX450hL, Lexus TX550h+, and Toyota Highlander models. Part number 902-5212 is also referenced as 1603131040 and Motorad 1040-180 for the same application.

Common Repair Uses

• Coolant seepage at the thermostat housing.
• Cracked or heat-damaged plastic housing.
• Temperature control issues caused by a worn thermostat.
• Leak repair on integrated thermostat housing assemblies.
• Replacement for a damaged sealing surface or outlet connection.

Installation Notes

Verify the vehicle uses the integrated cover style and confirm the mounting pattern, outlet count, and thermostat specification before installation. The assembly includes a gasket seal and thermostat; mounting hardware is not included. Follow proper cooling-system service procedures, refill with the correct coolant, and bleed air from the system as required.

Quality Assurance

Dorman designs this replacement housing to match stock fit and durability on the listed applications and to withstand extreme temperature changes for extended service life.