Motorad CH1086 Engine Coolant Thermostat Housing - Lower

Engine Coolant Thermostat Housing for Lexus Lower Cooling Service

Motorad CH1086 is a metal engine coolant thermostat housing built for lower cooling system service on select Lexus applications. It is manufactured to OEM quality standards by an OE supplier and validated for thermal shock and leak resistance to support dependable coolant flow control.

Key Features

• Metal construction with a silver finish
• Lower thermostat housing application
• Outlet port diameter: 2.11 in
• Inlet port diameter: 1.26 in
• Mounting hole quantity: 5
• Bolt hole center to bolt hole center: 5.79 in
• Flange thickness: 0.52 in
• Outlet port quantity: 7
• Gasket or seal not included
• Bolts not included

Detailed Description

Motorad CH1086 is an engine coolant thermostat housing for Lexus GS300, GS350, GS450h, IS250, IS300, IS350, RC300, and RC350 lower cooling system applications. This housing is built from metal for strength and dimensional stability, with port sizing and mounting geometry that match the listed OE-style applications. The part number CH1086 is also referenced by interchange numbers 9CH1086 and 16304-31037, making it a direct replacement option for the specified Lexus fitments.

This part cross-references 9CH1086 and 16304-31037 for the same application.

Vehicle Fitment

• Fits 2018 Lexus IS300, Lower; includes housing and housing cap; to 10/2017.
• Fits 2018 Lexus IS350, Lower; includes housing and housing cap; to 10/2017.
• Fits 2018 Lexus RC300, Lower; includes housing and housing cap; to 11/2017.
• Fits 2018 Lexus RC350, Lower; includes housing and housing cap; to 11/2017.
• Fits 2016-2017 Lexus IS300, Lower; includes housing and housing cap.
• Fits 2006-2017 Lexus IS350, Lower; includes housing and housing cap.
• Fits 2016-2017 Lexus RC300, Lower; includes housing and housing cap.
• Fits 2015-2017 Lexus RC350, Lower; includes housing and housing cap.
• Fits 2013-2015 Lexus GS350, Lower; includes housing and housing cap.
• Fits 2007-2011 Lexus GS350, Lower; includes housing and housing cap.
• Fits 2006-2015 Lexus IS250, Lower; includes housing and housing cap.
• Fits 2007-2011 Lexus GS450h, Lower; includes housing and housing cap.
• Fits 2006 Lexus GS300, Lower; includes housing and housing cap.

Common Issues This Part Addresses

• Cracked or warped thermostat housing
• Coolant seepage at the housing flange
• Improper thermostat sealing at the lower housing
• Cooling system service on Lexus engines with worn housing surfaces
• Replacement after leak testing confirms housing failure

Installation Notes and Tips

Verify the lower housing location, port dimensions, and mounting pattern against the removed part before installation. Because the gasket or seal is not included, transfer or replace the sealing components as required for the repair, and inspect the mating surfaces for corrosion, pitting, or distortion before reassembly.

Quality Assurance

Motorad manufactures this thermostat housing to OEM quality standards as an OE supplier. The housing is thermal shock validated and 100% leak tested to help confirm material integrity and sealing performance before installation.