Cooling System
Thermostat Housing
A thermostat housing holds the thermostat in place and connects it to the radiator hose. We stock 32 housings from $14 to $231 for 1986-2021 vehicles, from AC Delco, Dorman, Motorad and Brock. Fits include the Chevrolet Camaro and Cruze, Mini Cooper, Jaguar, Mazda and Ford models.
Shop thermostat housing by vehicle
Replacement Engine Coolant Thermostat Housing Assembly 121-253A121-250
Fits 2007 models
Dorman Water Pump Engine Coolant Thermostat Housing Assembly 902-812
Fits 2013 models
Replacement Engine Coolant Thermostat Housing Assembly 121-299
Fits 2016–2017 models
Why housings fail
Many modern housings are made of plastic, which becomes brittle after years of heat cycles. They crack, warp or leak at the seams. Metal housings can corrode, especially if the coolant has not been changed on schedule.
Watch for coolant drips near the hose outlet, crusty white or green residue on the housing, a sweet smell after driving, or a falling coolant level. A leak here can lead to overheating if it is not fixed.
What is in the box
Package contents vary a lot. Some listings are a bare housing with a gasket. Others are a complete assembly with the thermostat and a temperature sensor already installed. A few include O-rings, a water outlet and a separate thermostat.
If the housing includes a thermostat, check its opening temperature against your engine's specification. Choosing a complete assembly saves you transferring parts and avoids reusing an old thermostat or sensor.
Installation advice
Let the engine cool before you open the cooling system. Drain coolant below the housing level, then remove the hoses and bolts.
Clean the mating surface well and use the new gasket or O-ring. Plastic housings can crack if the bolts are overtightened, so torque to the factory spec. Refill with the correct coolant type and bleed the air out. Check the position field, such as lower or water pump, and confirm your engine in the fitment table.
Thermostat Housing questions
Can I just replace the thermostat and keep the old housing?
If the housing is not cracked or warped, yes. If it is plastic and showing leaks, residue or distortion, replacing it at the same time avoids a second job.
Does the housing come with a new thermostat?
Some do. Many listings are complete assemblies with the thermostat and sensor installed, while others are just the housing and gasket. Check the package contents.
Why does my plastic thermostat housing keep cracking?
Plastic housings age with repeated heating and cooling. Overtightening bolts, using the wrong coolant or old hoses can also add stress. Replace with the correct part and torque to spec.