You have a failed gasket, seal, or hose.
That means the engine is running HOT. Need to check the coolant level and check for coolant leaks.
If by water you mean engine coolant, yes. Loss of coolant, antifreeze, is a major cause of overheating.
It means low coolant. Top it up with water; and if it still leaks then maybe theres a hole in the container
Where? Be more specific? Try to put a bit more detail in your question top of the engine could mean anything.
You have a coolant leak.You have a coolant leak.
The water pump is worn out. Time for replacement.
Anything that can be burned to run a diesel engine.
The coolant level is low.The coolant level is low.
white smoke from diesel exhaust generally means you have engine coolant leaking internally in enginevery rarely , white smoke can indicate a problem with the turbo
There's a leak somewhere in your coolant system. Check the radiator and the hoses.
If, by "thermostat" you mean the radiator flow valve that controls engine coolant temperature, yes. All liquid cooled engines need such a thermostat.
Flex fuel does not mean you can use diesel. It means the engine can run on pure gasoline or on E85 gasoline. If you put diesel in this vehicle it simply will not run. Diesel can only be used in a diesel engine.