It started out with the heater only heating while driving and no other problems. I replaced the thermostat and coolant but I couldnt get the system bled right so I brought it to the steeler-ship for a flush since it hasnt been done anyway. I had to take it back 3 times because as soon as i started the car one of the fans was running and as soon as I accellerated onto the freeway I could watch the temp climb to full hot. like i said, I took it back 3 times and ended up finishing the bleed myself. The temp is normal all of the time now but the fans keep coming on once it warms up even if its cold outside. Before all of this neither of the fans would hardly ever run, even on 100+ days.

My guess is that the temp sensor for the temp guage is at a different location than the sensors for the fans and that there may be air somewhere causeing the fans to read inaccuratley.

 

I had same exact issue. Its air. My car sounded like it had ac on the whole time and it wouldnt stop. I popped open the radiator cap and it let some air out. Then i added coolant. Problem gone

 

The Z is tough to bleed all the air out of. Check the Bleeding instructions at the bottom of this page... http://crackaddict.com/~flynn/howtos...amco.howto.htm

 

I thought that I should post a fix in plane site since that never happens on any of these sites.

I replaced the radiator with a Mishimoto which didnt fix it.

I replaced the thermostat for the 3rd time with an OEM one and that fixed it. I drove the crap out of the car up HWY 2 and the a/c blew cold air from top and bottom the whole time in head and foot re-circulation mode up to 75 degrees selected. It used to start blowing warm air at the feet anywhere above 60 (minimum selection). The actual Nissan thermostat is well worth it at 10 bucks more than the local parts shop.

Now I have another problem. The "service engine soon" light is on with a missing gear indicator light and a severe loss of power. This one is for another thread. Please respond to the new thread with any answers.

Thanks,