Why is there oil in my radiator?

1992 sedan deville cadillacWhy is there oil in my radiator?
this is most often from a bad radiator that has the trans cooler line built in it. the cooler starts leaking into the coolant. the next possibility is a cracked head and the oil is being mixed in the coolant around the cylinders. has your car overheated recently? this is almost always where it started with the cylindr leak condition. also does it run badly? the trans leak wont make the engine itsself run bad but eventually destry the transWhy is there oil in my radiator?
Head-gasket is going. It will take a while when it is completely gone. The symptoms, less power, consumption of more oil and filling more water in radiator, you will notice more white smoke coming through exhaust. Either you have to get it repaired or buy the half reconditioned engine. There is no other cheap remedy. Sometimes it works with STP (very thick oil type solution readily available for this purpose from retailers), not very reliable, you may try.
I saw someone pour oil into their overflow reservoir once but if you didn't do that, it's the head gasket.
Either the transition cooler is leaking, or you may have a head gasket starting to let go.
blown head or blown head gasket
could be a cracked block, check to see if there is anti- freeze in your oil.
Blown head gasket