Parts for your 2017 Toyota Vitz|yaris-Thermostat

2017 Toyota Vitz/Yaris Thermostat — What it does and when to swap it

Technical sources confirm a thermostat is absolutely fitted to the 2017 Toyota Vitz/Yaris. Toyota’s repair manual for the XP130 series (covering 1KR-FE 1.0‑litre, 1NR-FE 1.3‑litre and 1NZ‑FXE hybrid engines) details a wax‑pellet thermostat in the water inlet housing, and the Toyota Electronic Parts Catalogue lists the thermostat assembly for these engines with an opening spec around 80–84°C. Trade data services such as Autodata also publish identical specs and test procedures, so it’s a core part of the cooling system on this model.

What does it do? The thermostat helps the engine warm up quickly and then stay right on its sweet‑spot temperature. It stays shut when the motor’s cold so the coolant heats up fast, then opens progressively to route flow through the radiator once it’s up to temp. That means better fuel economy, steadier cabin heat, and reduced engine wear. On the Vitz/Yaris, the thermostat sits in the water inlet where the lower radiator hose meets the engine.

When should it be replaced? Toyota doesn’t set a routine change interval for the thermostat, it’s a replace‑on‑condition item. Swap it if you’ve got slow warm‑up, the gauge wandering, poor heater output, or overheating at highway speeds. It’s also smart to replace it whenever the housing or water pump is off, or during a full cooling‑system refresh.

• Use a genuine‑spec thermostat and new O‑ring/gasket.
• Drain and refill with Toyota Super Long Life Coolant (pink) premix, and bleed air properly.
• Torque the housing bolts to spec and check for leaks with the engine hot.

A decent workshop will test opening temperature in hot water (thermostat removed), checking it starts to open around the published spec and fully opens a few degrees higher. Typical labour to replace is about an hour, depending on engine and access. If the coolant is older than the service window (Toyota SLLC is typically long‑life), do the coolant at the same time to save on labour and keep the system mint.

Tell‑tale signs it’s time: the temp gauge taking ages to reach normal, the cabin heater going cold at speed, or the fan running heaps with no real heat. Sort those early and the 2017 Vitz/Yaris will stay happy across big Kiwi and Aussie kilometres.

FAQ: What temperature does the 2017 Vitz/Yaris thermostat open at?

For the common petrol engines (1KR‑FE and 1NR‑FE), the rated opening is typically about 82°C, with full opening a few degrees higher. The hybrid 1NZ‑FXE variant is in the same ballpark. Always check the exact spec on the replacement part or in a current service manual.

FAQ: Where is the thermostat located on this model?

It’s housed in the water inlet where the lower radiator hose connects to the engine. On non‑hybrid models, that’s usually at the front/side of the engine bay under the alternator area. The hybrid’s layout is tighter, but the part still sits at the inlet housing fed by the lower hose.

FAQ: Should the thermostat be replaced as preventive maintenance?

It’s not a scheduled item, but many workshops will recommend replacing it during major cooling‑system work or if the vehicle has high kilometres and variable temperature behaviour. If the cooling system is being refreshed, doing the thermostat with fresh coolant and a new cap can be cheap insurance.