ummmm...not to point out the obvious...but that's coolant coming from your oil pan...that could explain a problem i have with my 89 Corolla GT-S...my temp gauge indicates proper temp and everything......and i just replaced my rad 2 months ago......but i smell coolant all the time when i get outta my car.....and it's an EVER so slow leak 'cause there's never any puddles of it under my car or anything...........i just topped up my rad the other day and it took MAYBE 1/4 litre of coolant...so that's how much i lost in two month.......and i don't know where it's going............where my tranny bolts to the block it's wet around where the gasket it......and it's a LITTLE wet around where the oil pan mounts to the block too but i looks like oil.........it's probably like your picture.......just not that intense!! and i don't see coolant...i don't have any overheating problems like you're having.........i feel bad for ya.....that's sucks man. i'm not sure how coolant can be showing comin' outta your oil pan like that.