Cooling Question (answer is in haynes manual)
 

I don't have my haynes manual anymore, nowadays i use the nissan mechanical cd. But I am having trouble diagonising my over heating problem and i believe the haynes manual had a simple way to tll if your water pump was going bad by checking whether the hoses were hot or something... Along with all my electrical problems (in other posts) my cars been overheating lately but in a strange way. It'll only do this about half the time i'm driving and sometimes it won't do it at all, but when i do get an indication that the car is overheating the heat gauge on the dash will only go to about 15 degree's (in angle) below the first hash mark for overheating. And no matter how hard i drive it, it'll never climb higher than "near" the overheating mark. But i know that when its not dead center where it should be, something is wrong so i'm trying to figure out where the problem is. I already changed the thermostat cause it was easy and because at first i thought it was the thermostat since i learned of the overheating problem by having the hose that goes to the thermostat explode on me. But the problem persists even with the new thermostat. So i'm thinking its probably the waterpump. I'm also hearing a whine coming from the engine that sounds like i have a turbo. I'm figuring that the pump but i want to make sure before i go through the pain in the *** of removing it. (i've done it before and it sucks!) So any surefire tests?

Very seldom do water pumps fail to circulate the coolant in a engine, but it is possible. This would be a mechanical failure of the vanes or bearings/shaft. The common failure is leaking from the weep hole, resulting in low coolant level and the resulting poor cooling performance.

The VQ water pump is of course driven off of the cam chain, so it is not likely to produce a whining noise due to failure as would a belt driven pump.