your way in over your head...first off dont ever let a mechanic say that i"ll just dump this powdery gold/aluminum looking liquid that will find those tiny cracks in your engine and also will start eventually to start clogging up a rusty old worn out radiator...you will need a new radiator $400 ,waterpump installed $220, check your engine oil see if it looks milky shake like,,,should be dark black if it don't look right your gonna need new head gasket $50 installed $500 . Is this an automatic?you might be able to save the transmission take it to a place that has the machine that will **** out all and i mean all the fluild, you should get them a transmission filter kit and watch them change it out after the torque converter has been sucked dry..then the can reservice it and have it cycled through park/drive 123 gears etc, this service probably$200 maybe more. then you need to run a radiator cleaner fluid before installing a new one drain it out and then have the new radiator installed and pressure checked..your looking at close to $1400 to get it working right.