You answered your own question really. If speedfan, bios, and realtemp are all reporting excessively high temperatures,and your heatsink is cool to the touch, it must not be making proper contact with the chip end of story. If thermal transfer from the chip to the fan was taking place, the heatsink would be warm or hot to the touch with the temps your talking about.
The push pin method is horrid, you most likely have one or more pins not fully secured to the back of the mobo.
It's a pain in the arse, but I would remove the mobo(unless you have a case with a cpu cut out) and reinstall the fan. Then verify all four of the plastic fasteners are fully through and attached securely. Just a little paste in the middle is enough btw, after cleaning both the chip and the fan with some rubbing alcohol.