Parts for your 2015 Suzuki Splash-Thermostat

2015 Suzuki Splash thermostat: what it does and how to look after it

Technical sources confirm the 2015 Suzuki Splash is fitted with an engine coolant thermostat. The Suzuki Splash/Ritz workshop manual (Cooling System section) describes a wax‑pellet thermostat in the outlet housing, and the Suzuki Electronic Parts Catalogue lists a thermostat assembly for K10B 1.0, K12B 1.2, and D13A 1.3 DDiS engines. So, a thermostat is absolutely relevant on this model.

On the 2015 Suzuki Splash, the thermostat’s job is to help the engine warm up quickly and then keep it at a steady operating temperature. It stays closed when the engine’s cold so coolant circulates internally, speeding warm‑up for better fuel economy, smoother running, and good heater performance on chilly mornings. Once the coolant reaches the set temperature, the thermostat opens to let coolant flow through the radiator and shed heat. That balance stops over‑cooling on the motorway and overheating in traffic, while giving the ECU a stable temperature window for emissions and performance.

Modern Splash thermostats are compact assemblies, typically sitting in the outlet housing under the upper radiator hose. Many have an integrated bypass so coolant can circulate within the engine until the thermostat opens. When they start to fail, owners may notice slow warm‑up, fluctuating gauges, a heater that’s lukewarm, cooling fans running at odd times, fault code P0128, or, in stuck‑closed cases, overheating.

As part of routine servicing, the thermostat isn’t a scheduled “replace by kilometres” item, but it’s smart to assess it whenever the cooling system is opened, the water pump’s replaced, or if temperature behaviour looks off. When replacement is needed, always use an OE or high‑quality equivalent unit with a fresh O‑ring/gasket. Refill with the correct OEM‑spec, silicate‑free long‑life coolant (often the blue Suzuki Super Long Life type) mixed to the right ratio with demineralised water.

• Inspect for crusty deposits or staining around the housing and hoses.
• After any work, bleed air from the system and set the cabin heater to hot.
• Verify radiator fans cycle normally at idle with the bonnet up.
• Torque housing bolts to workshop manual spec and recheck for leaks after a few heat cycles.

Looked after properly, the Splash’s thermostat helps the little Suzuki run sweet as and keeps Aussie and Kiwi commutes drama‑free, summer or winter.

Popular questions

Where is the thermostat on a 2015 Suzuki Splash?

It’s housed at the engine’s outlet where the upper radiator hose meets the engine, under the bonnet on the gearbox side of the bay on most K10B/K12B cars. The DDiS diesel’s housing sits near the EGR cooler area. Two to three fasteners hold the housing, always let the engine cool fully before removal.

What are the signs the thermostat needs replacing?

Common clues include very slow warm‑up, a heater that never gets properly hot, temp gauge wandering up and down, fans running when the gauge looks cool, fault code P0128, or overheating/boiling if stuck shut. Any of these warrant inspection and a fresh thermostat with new seal.

Do I need to bleed the cooling system after changing it, and what coolant should be used?

Yes, bleed air out after refilling. Set the heater to hot, idle with the cap off until the thermostat opens and the level stabilises, and top up the overflow bottle. Use an OEM‑spec, long‑life ethylene‑glycol coolant compatible with Suzuki systems (commonly the blue Super Long Life type) at the recommended mix, and check levels again after a few drives.