i got a 96 contour, 2.5 engine and have been using 10-40 oil in it since 1996.. probably the heater core plugged up.. you said it was leaking coolant, bet the previous owner used some of that oatmeal stuff they put in radiators to stop leaks.. it does not work(well it stops the leak but blocked up the passages of the radiator and heater core)..
go to auto zone and buy a Haynes book for the Contour, cost me $12.00 for mine back in 96...... it covers a few years on the contour... hope this helps.
