First of all it depends on what is wrong, if its a head gasket, thats fixable, might be expensive but fixable if thats all that has to be replaced. Usually when head gaskets go out they can warp the cylinder head too because of the high heat, because the coolant keeps going out the tailpipe, and if the head is warped then it gets more expensive. If its a crack in the cylinder wall it would probably be cheaper and more feasible to change out the engine in my opinion. Not sure how much 4 cylinder engines go for now a days, would just have to do some shopping around for a good price. Dont mention any of these possible repairs until you get the final verdict, dont need the shop tryin to charge you for a repair that is not necessary.. So hold back till you hear what it is, even then if you suspect or question anything, come back and we can verify anything the repair shop says as far as repairs go...