You can operate a car without an expansion tank but it will most likely drip engine coolant onto the road when the motor heats up.
Antifreeze/Coolant is a fluid that prevents the car from overheating or becoming so cold that it won't start. Without it, in the summer, your car would run too hot, and in the winter, your car wouldn't run at all.
Check the condition of your coolant, also noting the level of it. Without coolant, your car will run hot, and the water pump will not get lubricated and may cause a failure.
.
drive it without coolant
head gasket failing
When the car is cold the thermostat is closed. When the thermostat is closed the coolant does not circulate or get in to the engine block.
No, you run the risk of destroying the motor.
Run a pressure test on it.
After coolant is added run vehicle to normal operating temperature and re-check coolant level
It can run but if it is leaking coolant it will cause a problem soon.
Yes, it will self destruct without coolant.