Oil in water or trans fluid in water?

[Bates]

Brown sludge under the rad cap slightly white. Rad has just started leaking badly so could it be trans fluid getting into the water or would it be intake mani gasket or head gasket still?

[vn1989]

when i got my car it has trans fluid in the water cause the inside of the radiator was eaten out had to flush the motor like 3 times to get it all out and leave the transmition pan off over night to drain put a new radiator in filled it up and its all good... it was a kind of whitey pinky coloured blobs of tans fluid in the water