Pontiac Repair: Overheating, blown head gasket, themostat


Question
Hi Wayne,I have a 1995 Pontiac Grand Am ,with 125,000 miles on it. The car has been running hot lately ,so I had it checked out at a garage ,the mechanic told me that this make of car usually starts running hot after 100,000 miles,Two questions I would like to ask ,one ,is this known to you ,as far as for a car to start running hot after 100,000 miles? He said he also found oil in the radiator,does this mean blown head gasket? Should I change my themostat,I have no idea when it was changed last,and what else can you suggest I check or do .I really would apreciate any advice or instruction .Thank you  for your time Wayne and have a nice day,Ken

Answer
Hi, sorry for not answer befor now but the computer has been down. This could be a headgasket. have a cylinder comperssion check.  this will tell if the gasket is blown
on the 100.000 miles I don't no of any doing this just because it has reached the 100.000 mile mark. Not knowing what size engine you have, it's hard to say.