Originally Posted by 1993F250
So on another forum people are saying the Xterras don't act different when they're overheating which I find odd. And There sayin it sounds like I need to get a SC Xterra radiator.
Also I checked my fan, it's working.
I have had mine hot enough to engage the fault safety and up until it restricted me to 1500 rpm's it ran fine. The SC radiator definitely helps out, I have one and the temp never moves, but I would find what is causing the problem before installing the SC radiator.
Just because the centrifugal fan is turning does not mean it is working at the proper speed.
From top to bottom I would be looking at the following.
Is the coolant system topped off and properly purged of air?
Is the coolant clean and in spec on mixture?
Is the radiator it self externally clean and not plugged with debris?
Is there excessive corrosion inside the radiator?
Is the radiator cap in spec? Radiator caps wear out over time and will not hold the correct pressure. This will lead to overheating.
Is the thermostat installed correctly and opening at the correct temp?
Is the fan working properly and turning at the correct speed?
Is it really overheating? Do you have access to an infrared heat gun to check the temp at normal levels vs temps when the gauge indicates overheating temps?
Is the temp gauge reading properly? This is actually a common issue on the Gen 1 Xterra's. The connector for the temp gauge sender is affixed with a single rivet and over time the spade connector will work itself loose on the rivet. This will cause intermittent signal and wildly varying readings. Simple to check for and simple to fix. Just grab the connector and see if it will rotate in a circular manner. If so replace the sender. Make sure you check the correct sender as there are two side by side. One is gauge temp sender and the other is the temp sender for the ECU. The gauge is the one closest to the grill.
Gauge sender indicated by the blue arrow and the ECU by the red arrow.