Pontiac Repair: engine overheating, manifold gaskets, blown fuse

Question
I have a 2000 Grand Prix 3.8L. After running it for awhile the car goes into "limpmode". It starts to misfire and idle rough. The temp. light comes on. The temp. gauge is reading normal but when I checked it with my scanner it says it is running about 280 degrees. What should I be checking? Temp sensor?

Answer
Hi Chad.
Don't belive the gauge trust the temp sensor for the engine computer. First off make sure the cooling system is full If it's low a likley cuase is the upper intake plenuim leaking or lower intake manifold gaskets possably a water pump also? If the system is full the next thing to check is the fan operation. if the car has a/c and it still owrks turn it on assuming it's warm enough out for it to turn on. after a short period of time the fan(s) should turn on. if not then you could have a fan bad,relay,blown fuse any of those.. If you have a bi-directinal scan tool youi should be able to command the fan(s) on if it's just a code reader then it will not do that.  That is where I would start looking. Good luck :)