Thermostat Question

[yarista]

Does anyone know for sure whether the thermostat in my 07 Yaris will stick open or stick closed in the event that it fails?

[CTScott]

It really can fail either way, but I think it would more likely stick closed.

[vostorga]

Originally Posted by CTScott

It really can fail either way, but I think it would more likely stick closed.

In my own experience and as ctscott said, when the thermostat of my Yaris failed, it was closed.

[IllusionX]

If your car takes longer than usual to warm up in the winter.. it's likely sticking open.

[esse10]

In my past experience when folks mix the wrong coolant in the system it corrodes/rust the thermostat and it fails open, or actually there is gunk keeping it slightly open and makes the car's coolant system run colder than normal.
only use the coolant specified for your car and only mix distilled water to avoid problems.

[Geoff Peace]

Originally Posted by yarista

Does anyone know for sure whether the thermostat in my 07 Yaris will stick open or stick closed in the event that it fails?

As said it can stick open or closed. If it sticks closed there is no coolant circulation and the engine will soon overheat. In this instance, put the heater full on and the heater blower full speed to take some heat out of the engine. This may well save the head gasket. If it sticks open, then the engine will run cool and the heater will have poor performance. This is less serious in terms of damage but needs attention, i.e. the thermostat needs replacing as the engine will be inefficient and emissions will be high as a result. I hope this makes things a little clearer.
Regards Geoff Peace.

[TOLMACH]

stick open