BMW Repair: 2004 engine repairs that have not had good results, bmw north america, head gasket

Question
Have spent alsmost 5000k in one year to repair fule pump, thermostats and replaced the head gasket all to no avail,the car rides rough ,ticks and overhas easily and loses coolant if air conditioning is used and spews white smoke from the tail pipe if driven over 30 miles.recently told by BMW service that it would cost 3000k to see if the cylindar has cracked (it wasn't when head gasket was replaced) and if the crack is there 8000k to repair the engine. I own it and have 16 months left on the loan.BMW service said not to drive it every day   and would not recommend repairing the car as its 6rs old with 125k on it.BMW North America told me that I need to begin to take responsibility for this vehicle and will continue to expect their payments each month.What are my alternatives???

Answer
Well it sounds pretty bad.Why the cylinder head wasn't checked when the head gasket was done is a true sign of not knowing actually what was wrong.It probably was cracked back then.Driving it now it making it a timebomb.The check engine light I'm sure is on,if not flashing as well.The car needs repair done.I know you owe on it but it still needs to be paid.I wouldn't take it to the previous place,they missed it the first time and at 5 grand they should know better.If it was a dealership I would really make a fuss.I know its old in the dealerships eyes but to you it is not.Its your transportation and put repairs of extensive cost in their hands.....I would complain to the one who "FIXED" it