Overheating problem - new water pump, new thermostat, new radiator cap. Very intermittent, sometimes will hit the red mark in 300 feet of driving. Shut motor off, start back up 2 minutes later & the temp is normal. Other times will go several miles then hit red mark. Same thing, shut & turn back on 2 mins. later temp is normal. Does not act like a blockage when cooling off this fast. Could it be the coolant sensor or the clutch fan sensor?