Will no thermostat hurt the motor?

Answer 1

The function of the thermostat is an important one. When the engine is cold, the thermostat will let the cooling water circulate around the engine until it becomes sufficiently hot to enter the radiator. It opens at a certain temperature, and shuts when the temperature falls. If you remove the thermostat, the engine will take longer to warm up and may not get to the optimal running temperature, for example in cold weather or at night. The engine will in other words run colder than is ideal without a thermostat, and this will make the engine use more fuel. I am not sure if doing this will directly hurt the engine but it may do so over a long period of time. The only exception to this rule is some big motorcycles in tropical climates. The engines tend to become hot so quickly that removing the thermostat is sometimes done in order to prevent problems, such as a stuck thermostat. A stuck thermostat prevents the warm mater from entering the radiator and water pump and can cause the engine to overheat when the water starts boiling. This can also happen in cars of course but motorcycle engines are more vulnerable to damage and more costly to rebuild. It is a good idea to replace the thermostat every two or three years in a car to prevent a stuck thermostat.