Where is thermostat located on 1998 Acura TL?

In a 1998 Acura TL, the thermostat is located in the engine's coolant passage, typically housed in the thermostat housing. This housing is usually found on the engine's cylinder head, near the upper radiator hose. To access it, you may need to remove the upper radiator hose and the housing bolts. Always ensure the engine is cool before attempting to check or replace the thermostat.