Parts for your 2020 Mitsubishi Asx-Thermostat

2020 Mitsubishi ASX Thermostat — what it does and how to look after it

Based on technical sources — namely the Mitsubishi Motors ASX/RVR/Outlander Sport workshop manual (Cooling System section) and the Mitsubishi ASA electronic parts catalogue for the 4B11/4B12 engines used in 2020 models — the 2020 Mitsubishi ASX is fitted with a conventional engine coolant thermostat. It’s a wax‑pellet style valve housed at the engine’s coolant inlet/outlet to manage flow to the radiator, so it’s absolutely relevant to this vehicle.

The thermostat’s job is to get the ASX up to operating temperature quickly, then keep it steady. When the engine’s cold, the thermostat stays shut so coolant circulates within the engine, helping warm‑up and reducing wear and emissions. As temperature rises (typically in the low‑to‑mid 80s °C), the valve opens and meters flow to the radiator, preventing overheating. A healthy thermostat means better fuel economy, stable heater performance, and long engine life.

While the thermostat isn’t usually a routine “every X kilometres” replacement item, it’s smart to consider it whenever the cooling system is opened up or if there are temperature control issues. For the 2020 ASX, good servicing practice looks like this:

• Use the correct long‑life coolant specified for the ASX, don’t mix types, and replace coolant as per the owner’s manual schedule.
• Replace the thermostat and O‑ring/gasket if there are signs of sticking, corrosion, or if you’re already doing major cooling work.
• Bleed the system properly after any work: heater set to hot, fill slowly, run to operating temp, top up, and recheck the level when cold.

Common signs the thermostat may need attention include:

• Overheating or rapid temperature spikes under load
• Sluggish warm‑up, gauge sitting low, weak cabin heat, or higher fuel use
• Temperature fluctuating up and down at steady speeds

If replacement’s on the cards, a competent approach is:

1. Start with a cold engine. Safely drain enough coolant to drop the level below the housing.
2. Remove intake ducting or covers for access, then unbolt the thermostat housing.
3. Note the thermostat’s orientation (including any jiggle pin), fit a quality OEM‑spec unit with a new seal, and clean mating faces.
4. Reassemble to the correct torque, refill with the specified premix, bleed, and check for leaks and fan operation.

Using a genuine or OEM‑equivalent thermostat keeps the opening temperature and flow characteristics right for the ASX’s 2.0L/2.4L engines, which helps avoid nuisance faults and keeps the cooling system sweet across Aussie and Kiwi conditions.

Does the 2020 Mitsubishi ASX have a thermostat, and what temperature does it open?

Yes — the 2020 ASX uses a wax‑pellet coolant thermostat. The opening spec is in the low‑to‑mid 80s °C range, with full opening reached a bit higher. That keeps warm‑up quick and cruising temps stable.

Where is the thermostat on a 2020 ASX?

It sits inside the alloy thermostat housing on the engine, at the engine end of the lower radiator hose. Access typically involves removing some intake ducting and then unbolting the housing to reach the thermostat and O‑ring.

When should the thermostat be replaced on a 2020 ASX?

There’s no fixed kilometre interval. Replace it if there are symptoms (overheating, slow warm‑up, temp fluctuations), if the housing or seal is leaking, or proactively when doing significant cooling‑system work. Always follow the ASX owner’s manual for coolant type and service intervals.