Ok im working on this 99 Nissan and the issue is that the gauge shows the truck is over heating ,so we changed the thermostat ,the temp sending unit and that other thing next to that,and flushed the coolant system and bleed the system with new antifreez and fresh water for the correct mixture…The truck still says its over heating ,the top hose hot and the bottom hose not anything more then it is when the truck hassnt been running.
The truck starts right up and seems to run very well,then the gauge maxes right out and then wait for it to cool according to the temp gauge and drive a bit more,with in a mile its over heating again according to the gauge…I checked the oil and its perfectly fine and normal !
I am so lost here,the radiator is like new and the clutch fan works right ,checked all the hoses and they are not collapsing ,water pump replaced a year ago…Any ideas?
Do you hear the fan clutch roaring very loudly?
It should be, if the operating temperature is too high.
A defective new thermostat is not out of the question, either.
Have you replaced the cap?