exact same thing happened to me i bought the car then, about 3 weeks after owning it (driving from charleston s.c. to charlotte n.c. about 230 miles and several overheat breaks) i finally had time to get it checked out. it turned out to be a cracked cylinder. so i inquired about repairs and they gave me some bogus amount... so i bought a complete second engine and changed for a new gasket on it before i replaced it in my 98 gt... (along with waterpump and oil pump and thermostat) now engine runs fine no problems whatsoever and this fix cost about 1000 all said and done, doing my own labor. car now has 200k miles and an engine with half that. body looks like it has about 20-30k and same with interior. all said and done happier i did it myself and saved about $500 (to pay for at the time 2.50/gal gas and that was for regular!!!!)