Are you sure he didn't mean he is taking it out to replace it? Its purpose is to block coolant flow until it gets up to a specific temperature, typically 195 degrees F, then it allows it to flow to the radiator to give off its heat. Internal engine parts expand when they get hot and are designed to fit perfectly at that temperature. With no thermostat, the coolant won't get hot enough. You'll get cold air from the heater, contaminants in the oil won't vaporize and boil off to be burned. That results in sludge buildup and a loss of lubricating qualities in that oil. Emissions will go up due to incomplete combustion of the fuel.
What is the symptom the mechanic is trying to solve by removing a part? If the engine was overheating, it is due to a thermostat that fails to open, (or an unrelated problem with the radiator / fan). If the thermostat is defective, it gets replaced, not removed.
A common cause of overheating is a leaking cylinder head gasket. That can allow combustion gases to enter the cooling system. The gases pool under the thermostat causing it to remain closed when the engine warms up Thermostats open in response to hot liquid. They will not open in response to hot air. In this case removing the thermostat would prevent the overheating but it won't address the underlying cause.
Monday, October 28th, 2013 AT 3:47 PM