An engine's thermostat regulates the temperature of the engine by controlling coolant flow, its job is to block the flow of coolant to the radiator until the engine has warmed up.
Symptoms of a bad or failing thermostat: high temperature reading and engine overheating; low temperature reading and underheated engine; temperature changing erratically; coolant leaks around thermostat housing or under vehicle.
NOTE: If the thermostat has a jiggle pin, check valve, or other feature to assist in bleeding air from the system in a vertical installation, the jiggle pin should be located at the north or 12 o'clock location.
Compatible with Subaru Vehicles:
2006-2007 B9 Tribeca
2003-2006 Baja
1998-2013 Forester
1993-2014 Impreza
2002-2014 Impreza WRX
2004-2014 Impreza WRX STI
1990-2019 Legacy
2000-2019 Outback
1992-1997 SVX
2008-2014 Tribeca
2015-2020 WRX STI
Replaces Part #: 21200AA072, 21236AA010, 21210AA080 thermostat with gasket.
NOTE: To ensure accurate fitment, please confirm your vehicle information in the above compatibility section and the description.