i have a 1996 a4 2.8 quattro and usually i have to keep putting water in my resevoir tank ever couple of months and i just replace the resevoir tank like 6 months ago and i know its not my radiator where should i check there looks like corrision around the hose leading to the resevoir tank !

 

the coolant also passed through the oil cooler, chech that hose connection.

 

my mechanic did say something about oil seals needing to be replaced would that be it>?