Ok first off i have a 91 s10 blazer 4x4 4.3

so as of late i have been trying to figure out this coolant issue.
after i drive it and its up to running temp no leaks none whatsoever.
i park, leave it over night and there is coolant everywhere on the ground.
so i popped the hood and see that it looks as though the hose going from the radiator to the top of the engine block is leaking at the thermostat. im saying that because the coolant seems to be localized to that area only. if i squeeze the hose i can see it kind of ooze out of the hose where it goes onto the housing on the engine block. also i should tell you all that by this point there is nothing left in the reservoir. so i pulled the hose off. it looks good. no tears or anything. i replaced the clamp. refilled the reservoir. driving is fine as soon as it cools off same issue coolant all over the ground and the block around the housing. im thinking maybe the gasket is bad? im not having any overheat issue with it. like i said its only after i have let it sit overnight.. it has been getting super cold so maybe the hose is shrinking and its leaking that way?? i know thats farfetched but it almost seems logical well with this thing magic elves drinking the coolant could be logical after all that ive had to fix anyway any ideas would help out a lot.. thanks!!

 

Try replacing the thermostat gasket, might as well get a new thermostat while your in there.