Parts for your 2008 Subaru Exiga-Thermostat

2008 Subaru Exiga Thermostat — What It Does and How To Look After It

Yes, the 2008 Subaru Exiga runs a conventional engine thermostat. This is confirmed in Subaru’s factory service information for the YA-chassis Exiga (Cooling System section), the Subaru FAST electronic parts catalogue, and common workshop data used across Australia and New Zealand (e.g., Autodata/HaynesPro), all of which list and detail the thermostat and its service procedures for the EJ-series engines used in this model.

On the Exiga, the thermostat’s job is to help the engine warm up quickly and then hold it at the right operating temperature. It sits in the cooling circuit at the water pump inlet, controlling how much coolant goes to the radiator. Closed when cold, it gets the engine up to temp faster for better fuel economy and heater performance. As it warms, it opens gradually so the motor doesn’t overheat when you’re cruising up a hill or stuck in traffic on a hot arvo.

As part of routine servicing, it’s smart to keep an eye on thermostat health. There’s no strict replacement interval, but many techs in Aus and NZ replace it preventatively during major cooling system work—especially when doing a timing belt and water pump on EJ engines—because access is already sorted and the part is inexpensive insurance. Always use a quality OEM-spec unit and the correct gasket or seal.

• Common clues it’s on the way out: slow warm-up or the gauge dropping on the highway, spiky temperature swings, poor cabin heat, or overheating with a cold lower radiator hose.
• If replacing, work on a stone-cold engine, drain the coolant properly, clean mating surfaces, fit the new seal, and refit the housing evenly. Refill with the Subaru-specified long-life coolant (don’t mix types).
• Bleeding air matters on these: set the heater to hot, run the engine with the nose slightly elevated if possible, squeeze the top hose to burp air, and top up the header tank as the level settles.

Regular coolant changes at the intervals recommended for your Exiga and a quick look for leaks, crusty deposits, or hose issues under the bonnet will keep the thermostat and the rest of the cooling system happy for the long haul.

Where is the thermostat on a 2008 Subaru Exiga?

It’s housed at the water pump inlet, in line with the lower radiator hose at the front of the engine. Most techs access it from underneath after draining the coolant, then remove the small housing to swap the thermostat and seal.

What temperature rating should the thermostat be?

Use an OEM-spec thermostat matched to the Exiga’s EJ engine. Subaru service data specifies a temperature that begins opening in the high-70s to low-80s °C range, stick with the genuine or equivalent spec to avoid drivability and cooling issues.

Should the thermostat be replaced as routine maintenance?

There’s no fixed kilometre-based interval. Many workshops replace it proactively when the water pump or timing belt is being done, or any time there are symptoms like overheating, temperature fluctuations, or slow warm-up. It’s a low-cost part that can prevent bigger headaches.