Nissan Repair: overheating, radiator cap, fan clutch

Question
My 2000 frontier 4 cylendar over heats when driving 40 mph or higher speed. I have replaced radiator cap, fan clutch, thermostat, water pump and flushed it out real good. Also have removed any air from the system. I dont know what is left to do. Any idea?  

Answer
Rick,

Check the front of the radiator, see if the coils are smashed or bent in anyway.  If these don't have the right amount of air flow going thru, it will not cool down the engine properly.

Also, check the coolant fan.  If they are not coming on it will cause the car to run hot.

These are the only things I can think of about now.

"keep cool"

Darrel