Got a 99 Grand Prix with a 3800 "K" motor in my shop that ran hot. It was low on coolant so I topped it of and pressure tested the cooling system, has LIM leak. For ***** and giggles I ran it with the pressure tester on, the pressure rose pretty quick, probably has bad head gasket or head damage. To confirm this I tested it with a block tester. Sure enough, the tester fluid turned yellow, indicating exhaust gasses in the coolant. My thought is that he must have ran it pretty hot to damage something. There is no coolant/oil mixing, and when I tore the heads off the head gaskets looked OK. Im sending the heads off to be tested today. Ill post pics when I get home tonight.