my 2008 pathfinder is overheating and has no heating

are you losing coolant? you need to find the leak. if it is a hose or fitting then once it gets low and hot it will spray out onto the hot engine and steam there. It is also possible you have a bad stat.

I am having trouble with my 2006 pathfinder 4.0 overheating as well. I replaced the thermostat and both caps (radiator and reservoir). The system is pressurized and the #1 problem is reportedly the caps. Aftermarket caps are junk, my experience and all reviews I've read say that OEM caps and thermostats are the o my o es to be trusted. But I was still overheating, intermittently. Occasionally I would not heat and when I was overheating it would steam out from the reservoir (steaming when too hot is normal, to prevent catastrophic pressure build up). Further research pointed to the auxiliary pump which is on the drivers side, top of the engine compartment. When I bench tested, it tested fine. After much driving and troubleshooting on the side of a road I discovered that the auxiliary pump was o my coming on when the fan was turned on high. When the auxiliary pump is running I don't overheat, however I don't want to run with the heat on all summer. So I have a bad fan switch I guess. My suggestion would be to turn the key on, engine off and turn on the heater fan to different settings and see if it kicks on. If not, then apply 12volts to the two legs of the pump. It takes a second for the voltage to get the pump going. If the pump works then you have a bad fan switch or connection between the two. I am still having trouble though, does anyone know if the aux pump is supposed to be normally on, or normally off? My thoughts were that it should be normally off, kicking on only when you turn the fan on for heat. I replaced the water pump but the old one looks good, both fans seem to be working ok and I've burped the all the air out as far as I can tell. I am at a loss. Any suggestions?