Oil in coolant

Hello,

I have a 98 K1500 with that I has recently shown oil in the coolant overflow tank. Not being that familiar with these radiatiors, could this be engine oil or transmission fluid? I know I have the additional tranny cooler with the towing package. I have not noticed a loss in engine oil, but I have seen the tranny fluid go down. I previously thought this was leaking into the transfer case.

Thought I'd see if any one else has had this issue.

Thanks,

Eeewww, that cant be good... I belive the trans cooler is seperate from the radiator. Check your oil in crankcase, if it's milky or foamy BAD news. If it looks ok, check your trans fluid for the same conditions. Oil in coolant is not as bad as vice-versa!

it sounds like the trans oil cooler in the radiator has a leak in it . on the newer radiators one side cools the engine oil the drivers side i think. the otherside cools the trans oil. the plastic tanks can be pulled off and put back on.the quick couplings for the oil lines are simple to undo. pop the plastic cap off then work the clip out pull straight out on the cooling lines. reverse to put back together.don't know how much the oil coolers cost but they can be replaced too.