My 98 vicky started over heating on me.My mechanic told me my antifreeze was going out my tailpipe.Estimated head replacement repairs $2000.I havent got that kind of money on a fixed income.He mention a chemical that goes in the block and seals it,some times it works for a while he says.Woul it be cheaper to change the motor?I have had this car since last Dec,I'm gonna miss it.What do you think Bert?