AISIN Engine Coolant Thermostat Assembly THT-005 for Lexus & Toyota - Complete Housing & Gasket, OE-Matched Fit

This replacement thermostat assembly restores proper coolant flow and temperature regulation using AISIN's OE-matched engineering. Made from high-quality materials and calibrated to the correct operating temperature, the THT-005 is designed to deliver reliable fit, function, and longevity for affected Lexus and Toyota engines. The kit includes the thermostat, housing, and a new gasket for a single, straightforward service.

How does this thermostat help my engine warm up and stay at the right temperature?

The thermostat modulates coolant circulation by opening and closing at the specified OE temperature. That helps the engine reach optimal operating temperature quickly for efficient combustion, and then maintains that temperature by allowing coolant flow when needed.

• Opens and closes at the OE-specified temperature for consistent regulation.
• Precision valve action reduces overcooling and prevents overheating when closed or open as required.
• Thermostat housing and gasket included to ensure a proper seal and correct installation.

Will this fit my Lexus GS F, GX460, IS F, LC500, LS, LX570, RC F or Toyota Land Cruiser/Sequoia/Tundra?

The THT-005 is compatible with a range of specific Lexus and Toyota model years and engine configurations. Always verify fitment against your VIN or the vehicle fit checker to confirm compatibility because engine options and submodels can affect fit.

• Compatible examples: Lexus GS F (2016–20), GX460 (2010–22), IS500 (2022), LC500 (2018–22).
• Also fits Lexus LS460/LS600h, LX570, RC F and Toyota Land Cruiser, Sequoia, Tundra across listed years.
• Reference vehicle year and engine code; use the fit checker to avoid misfit.

What comes in the box and what should I expect during installation?

The kit ships with the thermostat, matched housing, and a gasket so you replace all sealing surfaces at once. Installation is straightforward for anyone familiar with basic coolant system service, though OEM torque specs and proper coolant bleeding are important for a leak-free result.

• Included: thermostat, housing, and gasket for a complete replacement.
• Recommended: replace coolant or top up per manufacturer guidelines and bleed air from the cooling system.
• Follow OEM torque specs and inspect hoses and clamps while access is available.

How does AISIN quality affect long-term performance compared with generic parts?

AISIN is an established OE supplier with design and manufacturing processes intended to match original equipment. That means tighter tolerances, correct operating temperatures, and durable materials, which reduce the chance of premature failure and coolant leaks compared with some aftermarket alternatives.

• OE-matched engineering for correct form, fit, and function.
• High-quality materials to resist corrosion and thermal cycling.
• Manufactured to AISIN's production standards and inspected for consistency.

Who is this for: The AISIN THT-005 thermostat assembly is intended for owners, mechanics, and fleet technicians maintaining compatible Lexus and Toyota vehicles who want an OEM-matched replacement. It’s suited for routine thermostat service, coolant system repairs, or when replacing a leaking thermostat housing. If you need reliable temperature control and a direct-fit component that includes the housing and gasket, this kit provides a complete solution engineered to original equipment expectations.