I have a 1996 hyudia elantra it is leakin water but do know where from

Replace the power steering belt. Make sure that it is tight.

You probably have a blown head gasket, and the water is getting into the cylinders.

White smoke normally indicates steam, did the car overheat ????...if it overheated check hoses for leaks,,,, loss of water etc

you could have a blown head gasket turning the water to steam as you drive,, feel inside the exhaust pipe to see if there is antifreeze residue there , the heater won't work without fluid in it to be heated and blown out into the vehicle. To check the head gasket have a compression check done on the car, any one or two cylinders lower than the rest means its shot, Hopefully its not a warped head

if overheats,and trows water or steam,there you can think on the water pump or the thermostat,but you only have a signal problem,try replacing the tempeture sensor.

What is the temperature outside when you start up in the morning? Is it cold....like in the low 40's?

it this a diesiel

you have a bad head gasket

Check Engine light? Whenever the "Check Engine" light comes on, there is always a DTC (Diagnostic Trouble Code) stored in the ECM (Engine Control Module). You'll need an OBDII (On-Board-Diagnostics) scanner to retrieve any codes recorded/set in ECM. Once you do this and let us know what it/they is/are, then perhaps we can help you. The throttle body is probably NOT the cause. Perhaps the throttle position sensor, or the Mass Air Flow Sensor, or perhaps a vacuum leak, OR, perhaps ignition wires or plugs or something else entirely. Best solution: take/tow the vehicle into a Hyundai Service Center (dealership), pay the diagnostic fee. They will tell you EXACTLY what the problem is and what's needed to fix it (parts, labor, tax, time-frame, etc.).