I am buying a '99 GP SE with a 3100 engine. It has 137K on it. The current owner says that his daughter had driven the car around for quite some time with the engine overheating. They replaced the thermostat and water pump, flushed the coolant and still over heated. So some of the local wrench guys said that the head gasket must be blown and, quite possibly, warped and/or cracked the head(s). With all this in mind, I went and checked out the car. Checked the coolant reservoir, no oil slick. checked the oil cap, no sludge, no sign of oil/coolant mix. Checked the dipstick, oil looks clean, no sparklies, no "milkshake" color. Started the engine and let it idle for 10-15 min. No overheat, in fact, it was running a little cold. Turned on the heater (max setting) and just cold air. Got in and drove the car around lots and side streets for about 3 miles. Floored it a few times to 50mph from standstill (couldn't go further...ran out of road) Tried my best to get this car to overheat. It never did. Now, keep in mind it was 34 degrees outside, (but when I blew the head gasket on my '95 GP 3100...the temp. was maxed out in 24 degree weather). Temp. gauge does fluctuate constantly and I could only keep the hot air coming out when ON the gas..the temp. needle would drop and hot air would come out of the console. If I let off the gas, the temp. needle would rise and the console air would go cold. However, the temp. gauge never rose above 210 for the entire drive, which took about 20 min. I am having serious doubts that this is a head gasket failure, but I am always open to other opinoins. Your thoughts?