steam is coming from thermostat?

Hello,

Typically if the thermostat is stuck closed you could see steam coming from the housing.
When you have a stuck closed thermostat it does not allow coolant to flow thru the engine and that will make the engine to overheat.

https://www.2carpros.com/articles/how-an-engine-thermostat-works
https://www.2carpros.com/articles/symptoms-of-an-overheating-engine

The best course to action would be to see if your engine is overheating. If so replace the thermostat. In order to remove the thermostat you will have to take off 2 bolts that is on the thermostat housing. Remember to only work on the cooling system when the engine is cool.
Be sure to clean out any gasket residue before installing the new thermostat.

https://www.2carpros.com/articles/replace-thermostat


Please let me know of any questions.
Thank you.