It could be a couple of things, there could be air in your cooling system. Im pretty sure that is isn't your water pump because on the neons the water pump is ran by the timing belt and if it seized up then it would snap the timing belt and your neon wouldn't run at all. It could be your thermostat. If it is stuck closed then it will not let the coolant through. That's cheap you should try that first, it is about $8 and you can do it yourself.
no a 2001 dodge neon motor will not work in a 2000 neon
Nearly all of the parts on a 2001 Dodge neon are interchangeable with the 2002 Dodge neon. The models are almost identical.
valves are not adjustable on a dodge neon.
Yes there is no difference in the two years 2001 was a carry over from 2001.
A Dodge Neon is port injected.
no
A 2001 Dodge Neon uses red, hoat type antifreeze.
no it will not the body style is different
Yes. A Dodge Neon uses R134a.
No, The neon was revamped in 2003, with updated engines and chassis changes. As a Chrysler mechanic, the 2000 dodge neon 2.4L DOHC is the best. That will fit in a 2001 also.
To pump the coolant through your engine, to keep it from overheating.
Check the coolant level. check the radiator fans.