Spring faces down toward engine.
when the thermostat will not open when placed in a cup of boiling water
There is no reason not to
Shouldn't be able to. If the thermostat is put in backwards, thethermostat housing will interfere with the thermostat. When placed in properly, the housing with install easily.
The thermostat on a 2001 Lexus RX300 is replaced by removing the upper radiator hose and unbolting the thermostat housing. The thermostat can then be removed, a new gasket installed, and the replacement thermostat placed in the housing.
Ok...this may be a little hard..! I identify the lower radiator hose, you will see two 8mm bolts attached to the thermostat housing. Like with every car, drain the coolant and do not do this with hot engine. You may need to tap the thermostat housing slightly with hammer to loose rust in bolts, geniuses at GM placed this part to close to exhaust manifold. Replaced with Stant Part # 42028 180 degrees thermostat. Only $8 at Advance auto parts. Gasket should be included or cost around $4 more. Fill the coolant reservoir, start engine, turn heater to high, add coolant as needed.
Spring into the engine.
One can change the thermostat on a Chevy car by draining the coolant and disconnecting the upper radiator hose. The thermostat housing is then unbolted, the old thermostat removed, and a new unit placed in the housing.
The thermostat is not in the lower radiator hose of a vehicle. Thermostats tend to be placed at the end of the lower radiator hoses, not inside them.
To replace the thermostat on a 1995 Ford F250, the non-working thermostat must be removed. The radiator hose must first be removed, then the non-working thermostat unbolted from the intake manifold. The area needs to be cleaned of any old seals and debris. The new seal needs to be placed in on the intake manifold. The new thermostat is then placed on top of the new seal and secured. The radiator hose is then reattached.