Because they are moving up and down thousands of times per minute.
Yes.
Yes.having low or no oil causes friction in the pistons which will cause car 2overheat.
The expansion of the heat from the combustion of the fuel drives the pistons.
Yes.
Yes, either can cause a shake while driving.
Yes, bad spark pugs or plug wires can cause the engine cylinder to misfire which will cause the engine to vibrate.
it depends. if the car isn't moving, but the engine is still on, then yes the pistons are moving. if the engine is off, and the car isn't moving, then the pistons are still.
Yes, a catalytic converter can cause a vehicle to vibrate and stall. It will do this when it gets plugged because it causes the fuel mix to be disturbed.
The most common cause is tire out of balance or bent wheel.
Cars vibrate.
It had a turbine engine, not a motor with pistons.
If the tires are properly balanced plug tires should not cause a vibration.