My 20 year old son has just bought a 99 Grand Prix, 65,000 miles on the 3100 motor. He did not take my advise to have the car checked by a mechanic. After a week he complains of no heat, so I check the radiator and lo and behold there is a shit load of stop leak in the system. I could check before he bought it because he was in a HURRY. The really bad thing is that his Grandfather pick this up at an auto auction and he never checked it before or after he bought the car( he trys to run a used car lot at his body shop). We flushed the system as best we could so he now has heat but we now wonder why this crap was put in there? I'm sure it isn't good. He took the car to get the oil changed and the shop said it needed intake gaskets. A friend of mine says it can't be that because there are no water jackets in the intake. I'm a bodyman and know little or nothing about mechanics. So, is it possible that its the intake or are we looking at a head and or head gasket problem. Thanks for any opinions,
Kirk