About this part
What it does. Aisin Engine Coolant Thermostat & Housing Assembly Aisin 170-THT-021 is part of the cooling system that carries engine heat away and holds the engine at operating temperature.
Symptoms that point to this part
- Temperature gauge climbing
- Coolant puddles under the car
- Heater blowing cold
- Sweet coolant smell
Fitment. Catalogued as fitting 2019–2020 Lexus Rx450hl. Engine, sub-model and trim can narrow fitment further, so check those attributes on the listing before ordering.