HouseCallAuto 10/3/2012The fan clutch might be seized and is spinning at full engine rpm instead of "slipping" as it is designed to do. The fan should increase it's speed with rpm and / or temperature. If the fan is spinning at full engine rpm the engine will sound like a jet engine and you will have a power loss as well, feeling hesitation.
HouseCallAuto 10/3/2012Raise the hood, leave the engine off and reach down and see if you can rotate the fan easily. It should feel resistance to turning, will feel hydraulic feeling, tight but able to turn with your filgers, but you should not be able to make it freewheel. If you can't turn it then it is seized.
HouseCallAuto 10/5/2012I think this car needs a look by a professional. The cooling fan may be operating at top speed to cool off the engine which is overheating for another reason. A bad water pump is not uncommon on this car and the water pump is electric.