could be bad piston rings,are your spark plugs oily,is your carb.tuned right,your intake manifold could be leaking
The engine will overheat and the pistons will seize.
The answer will depend on what engine it is and what it is being required to do.
It will overheat the engine
There is a warning light which flashes when the engine begins to overheat.
The engine is overheating.
If you allow the engine to overheat severally, yes.
No, but a lot more oil can cause other damage.
The engine will overheat quickly and catastrophic damage can occur if you continue to run the engine.
The engine will overheat.
Definitely
generally if an engine overheats, but then does not overheat when heater is turned on, is a good indication that the engine thermostat is stuck and needs replacing
if you run your engine without antifreeze your car will overheat and ruin the engine.