Chevrolet: Engine Overheating, clutch fan, chevy tracker

Question
I have a 2000 Chevy Tracker.  It has been overheating.  We have replaced the water pump, clutch for the clutch fan, several thermostats and a new radiator.  The vehicle continues to overheat.  What else could it be and how can we fix this problem

Answer
Terry;
HI - I would have a presshure test taken to see if there is a leak . Is there anything in front of the radiator to block the air? Is the oil clean or is there any white on the stick,if so you might have a cracked head or gasket.
Have you replaced the rad. cap.and is the tension tight enough to turn the fan w/o slipping.