Warm Laptop

So some time ago I cracked open my Thinkamapad R51 and cleaned the CPU off to get the thermal shit off of it. Replaced it with Arctic Alumina.

Dumb fucking question: It's now spewing out hot air whenever I plug the thing in. On battery power it's cool as a cucumber, and temperatures are nothing to be afraid of (~45C on load). Soooo what the Hell made it suddenly made it into a furnace?

Probably because the heatsink is now doing a better job of cooling the CPU down (heating up the heatsink instead) so now you get more hot air out the vent... ?

Just a wild guess.