My car has recently been overheating and allowing the internal computer system to shut it down to prevent blowing up the engine. I took it to the mechanic and he changed a few pumps and said the water was leaking. He put in a new thermostat and reset the computer system. Within the same month, the car did the same thing. High temperature occured after driving about 40 minutes in traffic and the computer system shut the car down. Took it back to the mechanic and he says that this is a different problem. He said that the overheating has caused a crack in the head gasket and that the coolant is leaking through the tailpipe. He wants $1500. Please let me know asap what this may be as I do not want to pay that much! I need a second opinion badly! Help!