Parts for your 2022 Subaru Outback-Thermostat

2022 Subaru Outback Thermostat: purpose, upkeep, and when to replace

Yes, the 2022 Subaru Outback is fitted with a conventional engine coolant thermostat. This is documented in Subaru’s factory service information for the Cooling section and corroborated by Subaru genuine parts catalogues for the 2022 Outback’s FB25 2.5‑litre and FA24 2.4‑litre turbo engines, both of which list a thermostat and seal/O‑ring as serviceable components. The thermostat sits in the cooling circuit to regulate engine temperature and is very much a relevant, in-use part on this model.

The thermostat’s job is to help the engine reach and hold its ideal operating temperature. When the engine is cold, the thermostat stays closed to speed up warm‑up. Once the coolant reaches its target temperature, the thermostat opens to let coolant flow through the radiator, shedding heat and keeping temps steady. That means better fuel economy, stable cabin heat, and protection from overheating under load.

On the 2.5‑litre FB engine found in most 2022 Outbacks, the thermostat is typically located near the water pump at the lower radiator hose side, tucked under the front of the engine. The 2.4‑litre turbo FA24 uses a similar arrangement. While the ECU controls the radiator fans, the thermostat itself is a mechanical wax‑pellet design, not an electronically controlled valve.

Thermostats aren’t a scheduled replacement item, but they should be inspected whenever coolant service is performed and replaced if there are symptoms of sticking or sealing issues. Always follow the service manual procedure for draining, refilling, and bleeding air from the cooling system, and use Subaru‑approved blue long‑life coolant. A new genuine thermostat and the correct O‑ring/gasket are cheap insurance against leaks and repeat jobs.

• Common signs it’s time to replace:
  • Slow warm‑up, heater lukewarm, or temp gauge sitting low (stuck open).
  • Overheating, rapid temp swings, or coolant pushed into the overflow (stuck closed or erratic).
  • Fan running more than usual, poor fuel economy, or fault codes for temperature plausibility.
• Good service tips:
  • Check for leaks and crusting around the thermostat housing and lower hose.
  • When replacing, clean mating surfaces, fit a new seal, and torque housing bolts to spec from the workshop manual.
  • Bleed the system thoroughly and confirm the heater blows hot at idle and on the road.

If the Outback’s temperature gauge is misbehaving or the cabin heat isn’t right, a thermostat and coolant check under the bonnet is a great first step. A competent home mechanic with basic tools can handle it, but an authorised Subaru service centre will have the correct procedure, coolant, and torque specs on hand.

Popular questions about the 2022 Subaru Outback thermostat

Where is the thermostat on a 2022 Outback?
It’s mounted at the front of the engine near the water pump on the lower radiator hose side. Access is from underneath with the undertray removed on many trims. Always verify exact location by engine code (FB25 or FA24) and consult the workshop procedure for safe access and coolant handling.

Does the 2022 Outback use an electronic thermostat?
No. The thermostat is a mechanical wax‑pellet type. The engine control unit monitors temperature via sensors and controls the radiator fans, but the thermostat itself opens and closes purely from coolant temperature.

How often should the thermostat be replaced?
There’s no fixed kilometre interval. Replace it if there are symptoms of sticking, overheating, or during cooling‑system repairs where the housing is already off. Pair any replacement with fresh Subaru‑approved coolant and proper bleeding to avoid air pockets.