Hello, I am on an errand for my father as he is not what you'd call "computer literate" hehe. Well, he's the owner of a 98 Cadillac Seville SLS with over 100k milage (not sure of the approximate), and he recently replaced the radiator over the summer and now it's experiencing some majoy overheating. The car will get to very high temperatures from a mere drive 'around the block'. My father is thinking there's a warped or blown head gasket, but I feel that seems unlikely. The car is without a thermostat as well, would this contribute to readings of overheating at all? We also suspect someting may have gone awry with the water pump, but the evidence is a bit inconclusive at this point. I read all about the subject on the forums here before posting this and saw such things as coolant problems, fan problems ect, but according to my father, these things are all running well, though he doesn't know if there is significant combustion in the coolant or leaking of water/fluids into other parts of the engine. If it is the head gasket, are they particularly easy to replace, and where could I find a guide for doing so, as taking it to a shop seems extremely expensive. Thanks for reading, I look foward to your responses.