I have a question about thermostats

[hz293]

the question is how does a thermostat allow an engine to overheat. I know that it stays closed until the engine warms up to a certain temperature then opens up. If the thermostat opened up shouldn't that allow seawater in to keep the engine cool. So what is it about a thermostat that can allow an engine to overheat

 

[poconojoe]

If it doesn't open the cool water is blocked from entering and the hot water is trapped and keeps getting hotter until kaboom....you need a new engine.

 

[500dollar744ti]

It doesn't really allow anything to happen, it just gets stuck closed and water can't circulate through the engine.

 

[thumpar]

It will only "let" the engine overheat if it is not working right. They open at a certain temp. It is not a common thing to have a thermostat fail. What exactly do you have going on?

 

[Volphin]

Most of today's thermostats fail open rather than closed. Only took them decades to figure that one out LOL.