Do you have a check engine light and when was last tune-up?
Fan not kicking on-On time-check the coolant temperature sensor or the engine temperature gauge switch-Losing power could be caused by the following below
March, 10, 2011 AT 2:20 AM
Fuel injectors dirty/sticking.
Mass airflow sensor/Airflow meter.
Throttle position sensor.
Crankshaft position sensor
Manifold absolute pressure sensor.
Fuel pressure regulator leaking or defective fuel pump.
Foul/defective spark plugs.
Open spark plug wires.
Ignition coil/Coil packs defective.
Incorrect ignition timing.
Cap and rotor.
Note: If it doesn't apply disregard it and keep testing.
March, 10, 2011 AT 2:22 AM
Has the Check Engine light turned on? To test the fan circuit, turn the ignition switch on, then unplug the two-wire coolant temperature sensor on the side of the thermostat housing. The fan should start running about two seconds later.
March, 10, 2011 AT 12:54 PM
No engine light isn't on. New oil and filter flushed radiator has new fluid. New plugs and wires. New thermostat for it, (but where the fans not kicking on till about the time it redlines if it turns on at all) I had to remove it just so I could get to town.