1995 dodge stratus smells like something burning, can't find any leaks. Smoke at back of motor. Temp gauge goes half way when I smell it. It never runs hot. What can this be???

Smoke (blue or black) or steam (white)? White smoke is really steam that is caused by water leaking onto hot surface. Could be leaking from hose running to heater coil under dash, or something else. Check radiator water level to make sure water level is ok. Blue smoke is oil burning. This could be dangerous, caused by similar scenario of oil leaking on a hot surface (from a gasket leak, etc), or exhaust fumes. Black smoke means something is actually burning and could indicate fire. Black or blue some could fill vehicle cabin with toxic fumes, even if you don't smell anything bad.

Could have an oil gasket leaking oil onto something hot.

Normally, white smoke is coolant burning.
Can you see any coolant leaks in the engine compartment ?

To me antifreeze smells like cat wee but look for oil leaking from there on to the exhaust. I would assume something is leaking on to the exhaust then burning off

make sure enough oil is in it. they may not have filled it up.a little oil may have spilled on exaust when oil was changed causing smell.

I am assuming that the smell, smoke and chirp are from under the hood.
That would be a pulley locked up, most likely the serpentine belt tensioner.

exhaust manifold leak or fluid dripping on exhaust.

Something is wrong. What does the steam smell like? Oil or antifreeze?
Look closely for coolant seeping onto something hot and vaporizing, if that's what you smell.
Check your coolant level and oil to verify if you may have a leak.

The fluctuation in the temp gage indicates a low coolant situation. The smoke you see from the defroster vent is actually antifreeze that is leaking from the heater core somewhere and as the antifreeze evaporates from the heat it causes a vapor to produce. You should smell a very sweet smell when you see the vapor. If so it is definitely antifreeze. Find the leak and fix it. Then refill your coolant system to specs and you should be good to go.