Where is the thermostat located on a Subaru?
In most Subarus, the thermostat sits inside the thermostat housing where the upper radiator hose meets the engine; the exact spot depends on the engine code. The precise location can vary by model year and engine family, so checking your specific engine layout is essential.
To locate it precisely, identify your engine code (for example EJ, FA/FB, or EZ) and consult the vehicle’s service manual or official diagrams for your model/year. If you’re unsure, a professional technician can confirm the exact location and access points for your particular Subaru.
Understanding where it sits on different Subaru engines
Subaru has used multiple engine families over the years. While the thermostat is typically found in a housing attached to the engine, some designs place the thermostat inside a shared housing with the water outlet or near the water pump. The layout is driven by the engine family and generation, so the housing style and exact position can differ from model to model.
- The usual starting point is the end of the engine where the upper radiator hose from the radiator connects.
- In many EJ-series engines, you’ll find a dedicated thermostat housing on the front or side of the cylinder head that the hose clips into.
- In some newer FA/FB or other late-model engines, the thermostat may be integrated into the water outlet or a combined housing rather than a separate, easily visible unit.
- If you’re working on EZ36 or other less common engines, the layout can differ again, so consult the exact diagram for your car.
Before examining the engine, look for the small housing where the upper radiator hose attaches to the engine. That housing commonly contains the thermostat in many Subaru designs.
Understanding these general patterns helps you locate the thermostat, but always verify with engine-specific diagrams for your Subaru.
How to locate the thermostat on your exact model
Use these steps to confirm the thermostat’s location on your specific Subaru model and engine code.
- Find your engine code (for example, EJ25, FA20, EZ36) in the owner’s manual, under–hood labeling, or on the engine block itself.
- Trace the upper radiator hose from the radiator toward the engine; in most designs, the hose ends at the thermostat housing—the likely thermostat location.
- Look for a small metal or plastic housing with one or two hoses attached and, often, a sensor screwed into the housing. This is typically the thermostat housing.
- If no obvious thermostat housing is found, inspect for a thermostat integrated with the water outlet or the front timing-cover area—the exact placement varies by engine family.
- Refer to the official diagrams or a repair manual for your year and engine code to confirm the precise location before starting work.
After locating the thermostat, if you’re planning replacement, remember to drain the cooling system appropriately, replace the gasket or O-rings as needed, and refill with the correct coolant type for your Subaru. If you’re unsure about any step, seek professional service.
Safety and maintenance considerations
Never work on a hot cooling system; allow the engine to cool completely before touching any hoses or the thermostat housing. When reassembling, tighten bolts to the manufacturer’s specified torque and dispose of old coolant properly. Consider replacing the thermostat, gasket, and any worn hoses at the same time to prevent future leaks.
Summary
Most Subarus place the thermostat in a housing attached to the engine where the upper radiator hose connects, but exact placement varies by engine family (EJ, FA/FB, EZ). Identify your engine code, consult engine-specific diagrams, and follow the hose path to locate the thermostat housing. If in doubt, rely on a service manual or a qualified technician to confirm the precise location and the proper replacement procedure. Keeping the cooling system in good condition helps prevent overheating and related engine damage.
