Keep your engine running at its designed operating temperature with the AISIN Engine Coolant Thermostat THK009. OE-manufactured for exact form, fit and function, it drops in as a direct-fit replacement for the 2001-2006 Hyundai Santa Fe, 1999-2004 Hyundai Sonata, 2001-2006 Kia Magentis, and 2001-2005 Kia Optima — all with the L4-2.4L engine.
The thermostat regulates coolant flow based on engine temperature: it stays closed while the engine warms up, then opens once the coolant reaches the set point to let it circulate to the radiator and hold the cooling system in its optimal range. This unit starts to open at 82°C (179.6°F).
- OE-engineered assembly: built as an exact replacement at the exact opening temperature to maintain cooling-system performance.
- Brass and stainless steel construction: durable materials for the operating environment.
- Jiggle pin check valve included: vents trapped air from the housing during refill to help prevent air pockets.
- Standard design; a gasket or seal is not included — consult the vehicle service information for the correct sealing components.
Signs the original thermostat may need replacing include the engine overheating (stuck closed), running cold or weak cabin heat (stuck open), or temperature-related warning codes. Country of origin: Japan.
Interchange: 310-0012 · 143-0722 · 25500-38001 · 545-180 · A2413-82G
3100012 · 1430722 · 2550038001 · 545180 · A241382G · 33996 · 48268
This part cross-references / interchanges with the following part numbers:
310-0012, 143-0722, 33996, 2550038001, 25500-38001, 545-180, THK-009, 48268, A2413-82G
