Being ur car I will guess has the original water pump that would be my first place to look.The pump has a weep hole and when the pump starts to go it will leak antifreeze.I recommend using some brake cleaner and clean the area around the pump bc this will remove residue and alloy u to see exactly if the pump is leaking.Granted the 2.8 pump may or may not be similar to a degree to mine with a 2.0 eng.Just clean the area and if the pump is leaking replace it.On my 85 it was easy to change out and should be similar with urs and if u change the pump you should flush the system and replace the hoses if over 4yrs old upper/lower (this is the rule recomm by hose manuf and I do this myself) and u might as well do the thermostat too.Hope this gives u a starting point.
