Whoa, 86C is very hot, too hot. Shut it down immediately! Make sure you reinstalled the hsf correctly after appyling as5. Most hs/fs suck air I think(edit I mean suck the air into the heatsink), but the difference is not that big, and which way works better depends on your system. I think the most likely problem is a botched hs/f installation. Make sure the hsf is contacting the cpu right. Take it off, reappy as5 to the cpu, install the hs/f, take it off and check if there is as5 on the heatsink. Put just a small layer of as5, not too much, enough to spread to a thin layer. And what mobo and monitoring program are you using?