PRODUCT DETAILS
Honda OEM Standard Thermostat - B/D/F Series Engines
Your old Honda's running hot or the temp gauge is bouncing around and you're wondering if it's the thermostat. It probably is. The thermostat controls engine temperature by opening and closing to let coolant flow through the radiator. When the thermostat gets stuck or fails it either stays closed and the engine overheats or it stays open and the engine runs cold. You're looking at an old car that's been sitting or driven hard for 20+ years. The original thermostat's probably toast. This is genuine Honda OEM part 19305-PAA-306. It opens at 87°C (183°F) which is exactly what came from the factory on your car. The thermostat assembly includes the housing, the valve, the spring, and a fresh seal so you're not dealing with a crusty old rubber gasket that's going to leak. Bolt it in and your cooling system's running correctly again. Direct replacement. No modifications. No guessing whether the temperature's right.
Here's What the Thermostat Does
The thermostat sits between the engine and the radiator. When the engine's cold the thermostat closes. It blocks coolant from flowing to the radiator so the engine warms up faster. That's why your car doesn't blow hot air out of the heater immediately when you start it on a cold morning. The thermostat's keeping the coolant circulating inside the engine so it heats up. Once the engine hits the opening temperature (87°C on this thermostat) the valve opens. Coolant flows through the radiator where it cools down. The cooled coolant comes back to the engine. The thermostat checks the temperature again. If it's still hot the valve stays open. If it cools below the opening temperature the valve closes again. It's constantly adjusting to keep the engine at the right operating temperature. When the thermostat fails it either gets stuck open or stuck closed. Stuck open means coolant's always flowing to the radiator so the engine runs cold. Your temp gauge reads low. You're not getting hot air from the heater. Your fuel economy sucks. Stuck closed means coolant can't flow to the radiator so the engine overheats. Your temp gauge climbs. You're getting warning lights. If you keep driving the engine gets so hot it can warp the head or crack the block. Don't drive an overheating car. Replace the thermostat.
87°C Opening Temperature - Factory Spec
This thermostat opens at 87°C (183°F). That's the exact opening temperature Honda engineered for B, D, and F series engines. Some aftermarket thermostats open at 80°C. Some open at 90°C. Some don't specify. You're not guessing with the OEM thermostat. You know it opens at 87°C because that's what the factory spec says. The engine's tuning, the cooling fan operation, the fuel injection mapping, everything's calibrated around 87°C. If you put in an 80°C thermostat the engine runs cold and the fan comes on too early and you're wasting fuel. If you put in a 90°C thermostat the engine runs hot and you're stressing the cooling system. The OEM 87°C thermostat is the correct spec for your car. No guessing. No hoping. Just the right temperature.
Includes the Complete Assembly and Seal
This isn't just the valve. This is the complete thermostat assembly. You're getting the housing, the valve, the spring, and a fresh seal. Some places sell you just the valve element and expect you to reuse the old housing and seal. That's garbage. The old housing's got corrosion inside. The old seal's probably cracked or hardened. You're just moving the problem to next month when the seal fails and the thermostat starts leaking. This assembly comes with everything. You're pulling the old thermostat out and dropping the new one in. The seal's fresh. The housing's new. You're bolting it down and you're done. No leaks. No surprises.
What You Get
- Honda OEM thermostat assembly - part number 19305-PAA-306
- Opens at 87°C (183°F) - factory specification
- Genuine Honda part - not aftermarket
- Includes housing, valve, spring, and fresh seal
- Direct replacement - no modifications needed
- B/D/F series engine compatibility
Fits These Cars
- 1997-1999 Acura CL
- 1990-2001 Acura Integra
- 1986-1990 Acura Legend
- 1990-2002 Honda Accord
- 1991 Honda Civic 5 Door
- 1992-2000 Honda Civic
- 1999-2000 Honda Civic Si
- 1997-2001 Honda CR-V
- 1991 Honda CRX DX
- 1993-1997 Honda Del Sol
- 2001-2003 Honda Civic DX/EX/LX
- 1995-1998 Honda Odyssey
- 1992-1996 Honda Prelude
Note: Standard thermostat for B, D, F series engines. Opens at 87°C (183°F) - factory specification. Genuine Honda OEM part 19305-PAA-306. Complete assembly includes housing, valve, spring, and fresh seal (not just valve element). Direct replacement - no modifications, no adapter housing needed. Thermostat controls engine temperature by opening/closing coolant flow to radiator. Stuck open = cold running engine, low temps, poor heat. Stuck closed = overheating, high temps, warning lights. Replace if engine running hot or cold. Don't drive overheating cars. Factory spec 87°C ensures correct cooling fan operation and fuel injection calibration. Not compatible with higher opening temps (90°C+) or lower opening temps (80°C-). Fits Acura CL, Integra, Legend. Fits Honda Accord, Civic (all years listed), Del Sol, Odyssey, Prelude.