So I just finished up my head gaskets, intake gaskets... etc. now I filled up the coolant, warmed her up. waited for her to cool off, pulled the radiator cap and there's oil floating on top of the coolant. i drained it off the top and after repeating this cycle a few times i realize it's not any spillage from my head gasket job. so i replaced my 8 month old radiator in hopes that it broke internally. i am confident that all my gaskets are in perfect condition. and now i have a new radiator that i'll check on in the morning. but i was wondering if anybody has an idea of where the oil could be from if i find more in the A.M. thanks plus i couldn't find a thread on "oil in coolant"






2000 ZR2 Blazer

 

Report back in the morning and let us know the results.

The oil cooler in the radiator is about the only place I can think of that oil can get into the coolant as the pressure of the oil in the cooler is higher than that of the coolant. In the engine block the coolant has higher pressure than the oil...

or so my understanding of it all goes. Good luck

 

when i opened the cap this AM there was a very trace amount probably left over. i warmed it up and am waiting for it to cool off to check once more.














2000 ZR2 - 2"body lift with gap guards, 1.5"lift shackles,T-bar tweak, quad beams, brushguards front and rear, off road lights, sun visor, 32/11.5/15 cooper discovery sst on American racing black steel -2 offset

 

yep changed radiator and the oil stopped!