Aisin THT-019 Engine Coolant Thermostat

Aisin THT-019 Engine Coolant Thermostat

The Aisin THT-019 engine coolant thermostat is an OE-manufactured replacement built for exact form, fit, and function. It uses a brass and stainless steel construction with an 82.0°C opening temperature to match the factory cooling strategy on many Toyota, Lexus, and Scion applications.

Compatible With Toyota Camry, Highlander, RAV4, Sienna, Tacoma, Tundra, Avalon, Venza, Matrix, Corolla, Solara, MR2 Spyder, Celica, 4Runner, and Lexus ES350, RX350, RX450h, RX330, RX300, ES300, LS400, SC400, and more listed applications.

• OE-manufactured replacement for factory-style fit and operation
• Brass and stainless steel construction for cooling-system durability
• 82.0°C start-to-open temperature, matching OE thermostat calibration
• Bottom by-pass design
• 52.0 mm sealing flange outside diameter
• No gasket or seal included

Detailed Product Overview

This Aisin thermostat is built for vehicles that require an 82°C / 180°F coolant control point, including many Toyota Camry, Highlander, and RAV4 applications as well as Lexus ES350 and RX350 models. The bottom by-pass design and OE-style dimensions help maintain proper coolant flow and engine operating temperature, supporting consistent warm-up and temperature regulation in daily driving and stop-and-go conditions. Part number THT-019 is also referenced in aftermarket catalogs for the same application.

Common Cooling Issues It Can Address

• Engine running cooler or warmer than specified
• Slow cabin heat during cold starts
• Temperature fluctuation during idle or traffic
• Thermostat sticking open or closed
• Cooling-system service on high-mileage Toyota and Lexus vehicles

Installation Notes and Tips

Verify the thermostat housing style, sealing flange diameter, and opening temperature before installation. Because no gasket or seal is included, reuse is not assumed; confirm the correct sealing component for the vehicle and housing. Clean the mating surfaces thoroughly and refill the cooling system with the proper coolant mixture after service. This part is listed for N/A position applications and should be matched to the exact vehicle fitment shown.

Quality Assurance

Aisin manufactures this thermostat to OE specifications for exact form, fit, and function. Cross-reference examples include Beck/Arnley 143-0722 and Gates 33868 for the same application. Part number THT-019 is listed across multiple aftermarket catalogs for broad Toyota and Lexus coverage.