Talking about this cooler?
Newegg.com - ZALMAN CNPS9500 LED 92mm 2 Ball Cooling Fan with Heatsink - Retail
CPU-z isn't accurate with voltage readings. So if you didn't touch the vcore setting, then I assume it's on auto.
The ambient temperature in the room, does play a big part, so your room must be pretty cold. In my room I always have the AC on, and I'm getting G0, so I'll probably get some good temperatures and overclock.
Show us some CPU-z screenshots for your overclock. Everest, Speedfan, or CoreTemp screenshots for your temperature.
What motherboard are you overclocking with, anyway?