Like another writer, I too have a 2001 Nissan Xterra that has had major overheating issues for over two years.
Almost every major element of the cooling system has been replaced, radiator, radiator cap, water pump, clutch fan, sending unit, thermostat, and still the problem persists. I live in Sol. Cal and it gets very hot here. I notice that the problem gets acute/severe when the air temp is over 95 degrees. Also, the overheating problem is most apparent when I am traveling uphill, as on grades and passes. The SUV doesn’t behave in any abnormal way - it doesn’t make noises, become sluggish, the a/c continues to cool well…It just reads very, very hot- up to the top of the normal scale. As soon as I crest a hill/pass, the gauge drops, like a rock, back to the normal readings.
I noticed that there was a discussion about this topic last March (2008) but the owner of the Xterra did not post the results of their attempts to solve the issue.
Please someone, HELP! I need SOLID answers.
Two things.
Going up hill and it’s worse might mean you have air in the system. Park the truck on a hill with the front end facing up the hill. Let it sit for a while with the radiator cap off. If there’s any air in the system it’ll find it’s way to the top of the radiator. If there is…just tap it off with coolant/water mix.
If that’s not the problem…try replacing the clutch fan with an electric one. There’s a kit for the Pathfinder…I assume there’s one for the XTerra.