97 audi a4 engine oil cooler.. please help.
 

i have a 1997 audi a4 1.8T automatic...
there is a good amount of oil leaking into the coolant system. I've been reading that the engine oil cooler could be leaking. (or the trans oil cooler, though it doesn't appear to be trans oil). Im trying to find out if the engine oil cooler is built in to the radiator or if it is separate. Also any tips on replaceing either the whole radiator/oil cooler would be so greatly appreciated. I need to take care of this in the most cost effective way possible. The car has been sold to a friend already, but i dont feel right leaving them with this problem. That being said, i am broke. Thank you so much for any help/advice that you can offer...