Parts for your 2021 Honda Odyssey-Thermostat

2021 Honda Odyssey thermostat — purpose, care and when to replace

Yes — the 2021 Honda Odyssey uses a conventional engine coolant thermostat. Honda’s Factory Service Manual (FSM) for the 2021 Odyssey J35Y6 V6, the Honda Service Information System (SIS) and dealer parts catalogues list a thermostat assembly in the water inlet housing, with a wax‑pellet valve that begins opening around the mid‑80s °C and is fully open near the low‑90s °C. Independent repair databases (e.g., ALLDATA/Mitchell) also show its location, operating temperature and replacement procedure. It’s a normal, critical part of the Odyssey’s liquid‑cooling system.

The thermostat regulates coolant flow so the V6 warms up quickly, then holds a stable operating temperature for performance, economy and emissions. When cold, it stays shut to speed warm‑up