Parts for your 2018 Suzuki Splash-Thermostat

2018 Suzuki Splash thermostat — purpose, fitment and servicing tips

Yes, the 2018 Suzuki Splash uses a conventional engine coolant thermostat. Technical sources support this: Suzuki workshop literature for the K10B/K12B engines fitted to the Splash specifies a wax‑pellet thermostat in the water outlet/thermostat housing, and both the Suzuki Electronic Parts Catalogue and major aftermarket catalogues (including Tridon in AU/NZ, plus Gates and Dayco) list a serviceable thermostat for these engines. So it’s a relevant, fitted component on this model.

On this little Suzuki, the thermostat’s job is to get the engine up to temperature quickly and then keep it there. It stays shut after a cold start so the engine warms up promptly, which helps fuel economy and reduces wear. Once the coolant reaches the rated opening temperature (commonly in the low-to-mid 80s °C depending on engine code and market), the valve opens to route coolant through the radiator, preventing overheating on long runs or hot days.

When a thermostat sticks open, the Splash can take ages to warm up, the heater runs lukewarm, and economy drops. If it sticks shut, the temperature needle climbs fast and the cooling fan runs overtime, left unchecked, that can cook the gasket or worse. That’s why a healthy thermostat matters for everyday reliability around Australia and New Zealand.

Thermostats aren’t usually on a fixed replacement interval, but on a 2018 vehicle it’s smart to consider proactive replacement if there are any cooling issues, during a major coolant service, or around the 7–10 year/150,000 km mark. Always match the opening temperature to the engine code, and use a quality O‑ring or gasket with a clean, corrosion‑free housing.

• Check symptoms: slow warm‑up, fluctuating gauge, weak cabin heat, or overheating under load.
• Inspect for leaks at the thermostat housing and perished hoses under the bonnet.
• If replacing, start with a stone‑cold engine, catch and dispose of coolant responsibly.
• Fit a new seal, align the jiggle pin (if present) to the bleed point, and torque bolts to the service manual spec.
• Refill with the correct long‑life coolant mix and bleed air, verify radiator hose temperatures as it warms.
• Scan for fault codes and confirm fan operation on a road test.

Location-wise, the Splash’s thermostat sits inside the thermostat/water outlet housing at the engine end of a radiator hose. Parts differ slightly between K10B (1.0) and K12B (1.2), so checking the VIN/engine code before ordering is the go.

Popular questions about the 2018 Suzuki Splash thermostat

What temperature does the Splash thermostat open at?

Most Splash thermostats for the K10B/K12B engines are rated in the 82–88 °C band, but the exact number depends on engine code and market. The rating is typically stamped on the thermostat itself.

For best results, match the new thermostat’s opening temperature to the original spec on the vehicle label or trusted parts catalogue. That keeps warm‑up and cooling behaviour just as Suzuki intended.

Where is the thermostat located on a 2018 Splash?

It’s housed in the thermostat/water outlet assembly bolted to the engine, where one of the main radiator hoses meets the cylinder head area. Follow the upper radiator hose and you’ll generally find it at that connection.

The housing contains the thermostat and seal, removing it reveals the valve. Space is tight on some variants, so having the right spanners and a fresh O‑ring ready makes the swap smoother.

Should the thermostat be replaced on a schedule?

There’s no strict time‑based schedule from most makers, it’s typically a replace‑when‑faulty item. That said, many owners choose to renew it preventatively with a major cooling system service or any time there are symptoms.

Given local climate swings in AU/NZ, replacing around 7–10 years or 150,000 km can be sensible, especially if you’re refreshing coolant, hoses, or a water pump at the same time.