Parts for your 2009 Suzuki Splash-Thermostat

2009 Suzuki Splash Thermostat: purpose, servicing and replacement

Based on Suzuki’s workshop literature for the Splash (covering the K10B/K12B petrol and D13A DDiS diesel engines) and the Suzuki Electronic Parts Catalogue, the 2009 Suzuki Splash is fitted with a conventional wax‑pellet thermostat housed in the engine’s coolant outlet. So yes, a thermostat is absolutely relevant and used on this model.

The thermostat’s job is to help the Splash warm up quickly and then hold a steady operating temperature, typically in the mid‑80s to low‑90s °C range. By staying shut when the engine’s cold, it speeds up warm‑up for better fuel economy, lower emissions and a decent heater under the dash. Once it reaches its set point, it opens and meters coolant flow through the radiator to keep temps stable, even on a hot Aussie or Kiwi summer arvo or slogging up a long hill.

As these cars age, the thermostat and its plastic housing seal can harden or stick. If it’s stuck open, the Splash may take ages to reach temperature, run rich, and the heater will feel weak. Stuck closed, and it’ll overheat quickly. Either way, it’s worth sorting early to protect the head gasket and keep the little Suzuki happy.

Thermostats aren’t a strict “replace by kilometres” item, but they’re cheap insurance when there are cooling issues, during a coolant change, or any time the housing is disturbed. Many techs will recommend replacement around the 10‑year mark or when chasing vague overheating/cold‑running faults. On the Splash, the thermostat assembly sits where the upper radiator hose meets the engine