I have an 87 4 door 2.5 liter. I get exhaust out of the radiator after it warms up and then eventually overheats. I tried using K&W block sealer in it but hasn't seemed to help. It runs great to my surprise.No smoke out the tail pipe, no coolant in the oil, no oil in the coolant, just exhaust pressure. But the cooling fans don't come on when it gets hot, so I run with the a/c on and the fans run constantly, but still overheats. I believe it to be the head gaskets, has anyone tried to change these before? I have done a good amount of wrenching, but this is an intimidating looking engine. I just got this car and have been very gentle because of the overheating, I would really like to see what it can do!