Parts for your 2011 Subaru Exiga-Thermostat

2011 Subaru Exiga Thermostat — What it does and when to replace it

Yes, the 2011 Subaru Exiga uses a traditional wax‑pellet engine thermostat. This is confirmed by the Subaru Exiga (YA series) workshop manual cooling system section and Subaru’s electronic parts catalogue for the 2011 model year, both of which show a thermostat fitted in the cooling circuit at the water pump housing. It’s a core bit of kit for the EJ-series boxer engines used in the Exiga, controlling coolant flow based on temperature.

The thermostat’s main job is to help the engine warm up quickly and then hold a steady operating temperature. When cold, it stays shut so the engine comes up to temp faster, reducing fuel use and wear. Once it hits its rated opening temperature, it meters flow to the radiator so the Exiga doesn’t overheat on long climbs or stuck in summer traffic. A healthy thermostat also keeps cabin heating consistent and helps the ECU maintain emissions and performance targets.

As part of routine servicing, a thermostat doesn’t need constant fiddling, but it’s smart preventative maintenance to replace it with a genuine-spec unit when the cooling system is opened up—say during a water pump or timing belt job—or if any symptoms pop up. Tell‑tale signs include slow warm‑up, temperature swings, overheating, a cold lower hose when hot, or heater performance that comes and goes. If the Exiga is still on its original thermostat after a decade or high kilometres, it’s fair to plan a fresh one.

Good practice when replacing the thermostat on a 2011 Exiga includes using the correct gasket/O‑ring, fresh long‑life coolant that meets Subaru specifications, and bleeding the system properly to purge air. Over‑tightening the alloy housing is a common pitfall—tighten evenly and only to the factory torque. Bleeding is crucial on the flat‑four: run the heater on hot, top up via the header tank, and allow the engine to cycle until bubbles stop appearing. After a couple of heat cycles, recheck the level under the bonnet and top up as needed.

• Choose OEM or OEM‑equivalent thermostat calibrated for the Exiga’s engine.
• Inspect hoses and the radiator cap at the same time, replace if perished or weak.
• Follow the coolant replacement interval for the exact coolant type fitted, many long‑life mixes are due around 5 years/100,000 km, while extended‑life Subaru coolants can go longer—always go by the label and service manual.

Popular questions about 2011 Subaru Exiga thermostats

Where is the thermostat located on a 2011 Subaru Exiga?

It sits in the water pump housing at the front lower section of the engine, behind the lower radiator hose. Access is from underneath or the front once the undertray (if fitted) is off and the coolant is drained. The housing cover comes away with a couple of fasteners, revealing the thermostat and its O‑ring.

What temperature does the Exiga thermostat open at?

The factory thermostat for EJ‑series Exiga engines begins opening in the high‑70s to low‑80s °C range, then is fully open a few degrees higher. Exact spec can vary by engine variant and market, so it’s best to match by VIN or use the value stated in the workshop manual or on the genuine part box.

Do you need to bleed the cooling system after fitting a thermostat?

Absolutely. Air pockets can cause hot spots, heater issues, and erratic temperature readings. Use a spill‑free funnel or raise the header tank, run the heater on full hot, and let the engine idle until the thermostat cycles and bubbles stop. After a couple of drives, recheck the coolant level and top up if needed.