Parts for your 2023 Mitsubishi Eclipse cross-Thermostat

2023 Mitsubishi Eclipse Cross Thermostat — What it does and how to look after it

Per Mitsubishi workshop literature for the Eclipse Cross (GK/GL series) and OEM/aftermarket parts catalogues used by dealers and trade repairers, the 2023 Mitsubishi Eclipse Cross is fitted with a conventional engine coolant thermostat. Both the 1.5‑litre turbo petrol and the PHEV variants use a wax‑pellet style thermostat housed in the cooling circuit, so the part is absolutely relevant to servicing and reliability.

The thermostat’s job is to manage coolant flow so the engine warms up quickly, then stays in its sweet spot under load, in traffic, and on long runs. By holding coolant back while the engine is cold, it helps reduce wear, improves fuel economy, lowers emissions, and gets the cabin heater blowing warm air sooner. Once operating temperature is reached (typically mid‑80s °C for this platform), it opens to route coolant through the radiator and keep temperatures stable.

There’s no fixed replacement interval in the service schedule, but real‑world experience says a thermostat is a “replace on condition” item. Signs it’s due include slow warm‑up, fluctuating temperature readings, poor cabin heat, the cooling fan running constantly, or overheating under load. A scan of the ECT (engine coolant temperature) with a diagnostic tool and a feel test of the radiator hoses can help confirm suspicions.

When replacement makes sense:

• After any overheat event, or when doing major cooling work (water pump, radiator, or housing reseal).
• Preventatively at high kilometres or around the 8–10 year mark, especially in hot‑cold duty cycles.

Good practice for the Eclipse Cross:

1. Use a quality OEM‑spec thermostat and new gasket/O‑ring for the housing.
2. Refill with the correct Mitsubishi Super Long Life Coolant (blue) premix at the right concentration.
3. Bleed the system properly to purge air, run the heater on high and top up the header tank as bubbles clear.
4. Tighten housing fasteners to workshop‑manual torque and check for leaks once fully warm.

Keeping the thermostat healthy helps the 2023 Eclipse Cross feel crisp on start‑up, tow and climb without fuss, and protect the turbo petrol or hybrid engine from heat stress under Aussie and Kiwi conditions.

Popular questions

Where is the thermostat on a 2023 Mitsubishi Eclipse Cross?
It’s housed in the thermostat housing on the engine—typically where a main radiator hose meets the engine block/water pump area. On the 1.5T, expect it near the lower hose outlet, on the PHEV, the location is similar within the engine’s cooling module. Access varies a bit with trims and under‑covers.

What temperature does the Eclipse Cross thermostat open?
The factory thermostat is designed to begin opening in the mid‑80s °C range and be fully open a few degrees higher. That lets the engine warm up quickly, then hold a stable operating temperature for efficiency and long life. Exact figures depend on the specific part number fitted, always check service data when ordering.

Should the thermostat be replaced when changing coolant or the water pump?
It’s smart to replace it during major cooling work or after any overheating. If the system is being drained for a water pump or housing reseal, doing the thermostat at the same time saves labour later. If there are no symptoms and kilometres are modest, it can be left, but test it and inspect seals while you’re there.