Parts for your 2016 Mitsubishi Asx-Thermostat

2016 Mitsubishi ASX Thermostat — What it does and when to service it

The 2016 Mitsubishi ASX uses a conventional engine coolant thermostat. This is documented in Mitsubishi’s factory Workshop Manual for ASX/RVR/Outlander Sport (Cooling System section) and reflected in parts listings within Mitsubishi’s ASA/ASA-CAPS electronic catalogue, which both specify a thermostat and housing for the petrol (e.g., 4B11/4J10) and diesel (e.g., 4N13/4N14) engines. Major aftermarket catalogues used in Australia and New Zealand (from cooling and belt system suppliers) also publish direct-fit thermostats for this model, further confirming fitment.

On this ASX, the thermostat acts like a temperature-controlled gate for coolant flow. When the engine is cold, it stays shut so the engine warms up quickly. Once operating temp is reached, it opens to let coolant circulate through the radiator. That keeps the temperature steady, helping fuel economy, performance and emissions, and protects the engine under load on hot Aussie or Kiwi days.

There’s no fixed “change-by” interval for the thermostat in normal servicing, it’s generally replaced if it fails or when related cooling work is being done. However, many workshops will recommend a proactive replacement once the vehicle is high-kilometre or if there’s been any overheating event. It’s smart to inspect it whenever the coolant is changed and to replace the thermostat’s O-ring/gasket if the housing is opened.

• Common signs it’s due: slow warm-up, running too cool, overheating, temp gauge fluctuating, weak cabin heat, or fault codes for coolant temperature plausibility.
• Good servicing habits: use the correct Mitsubishi-approved long-life coolant, check hoses and clamps, and bleed air from the system after any cooling work.

When replacing the thermostat on a 2016 ASX, a quality unit and fresh seal are a must. Under the bonnet, the thermostat sits in a housing at the engine outlet side of the cooling circuit (location varies slightly by engine). With the system cool, drain enough coolant to drop the level below the housing, remove the housing fasteners, swap the thermostat and seal in the correct orientation, then reassemble. Refill with the specified coolant mix, bleed air carefully, and verify stable operating temperature and heater performance on a test drive. Given how crucial temperature control is to engine life, a healthy thermostat is cheap insurance for everyday commuting and long open-road kilometres.

• FAQ: Where is the thermostat on a 2016 Mitsubishi ASX?

It’s mounted in the thermostat housing at the engine’s coolant outlet side. On petrol models it’s typically at the cylinder head/outlet neck leading to the upper radiator hose. Access can vary, removing the air intake ducting often improves room to work.

• FAQ: Does the thermostat need regular replacement?

It’s not a scheduled replacement item. Most are replaced only if faulty or when doing related cooling system repairs. After high kilometres or any overheating episode, many techs recommend fitting a new thermostat and seal for reliability.

• FAQ: What coolant should be used after thermostat work?

Use Mitsubishi-approved long-life coolant that meets the vehicle’s specification (common in AU/NZ is Mitsubishi Super Long Life Coolant or an equivalent premix). Mixing types isn’t advised, always refill with the correct spec and fully bleed the system.