My brother has a 2002 GTP that's had a hard life. It's clear to us now that the thing got in a wreck at some point before we owned it, and we have to pump money into it all the time. Lo and behold . . . we're having another problem with it. Driving along (60 mpg, cruise on) the temp will jump from regular running temp (~95) up to about 240, stay there for a few minutes, then come back down. It does this in a fairly regular and cyclical fashion. While I was away at school, he also had some A/C work done--I wish I'd have known about the A/C problems before he had it "fixed"--my newbie diagnosis is LIM gaskets and coolant elbows (I have a 2002 GP SE 3100 that had the same symptoms).
Interestingly enough, at about the same time he had the A/C work done the car started making a most interesting noise. The car sounds like s#*t when you start it, almost like a lawnmower. There's also a clicking sound coming from somewhere in the engine compartment that sounds like someone stuck a baseball card in the spokes of a bicycle. A friend of his told him the sound could be caused by the hose connecting the engine block to the radiator collapsing because of a blockage (sounds suspicious to me). Any thoughts on either problem? Thanks.