Oil in Coolant

HI,TODAY I WAS DOING A PM-SERVICE AND THE MECHANIC WAS TELLING ME,I HAVE OIL IN MY COLLANT.MY QUESTION IS,WHAT IS THE PROBLEM,THE MECHANIC TELL ME MAYBE IS THE OILCOOLER BAD.WHAT YO THINK. IS A CAT KCB -C 13 ,2006.I like to drive 3 weeks more and when I am Home to fix this Problem, can I do this without a Risk.The Truck runs normaland the Watertemperatur is normal.Thanks for you Answer

 

I don't have clue what the Problem is.When I am Home I have Time and my mechanic can fix this Problem easy.Only I was Home for 2 day and now iam on the Road.I have a load from MD to Maine.What you think is better to canceled this run to Maine,and find a Load Home (MIAMI)

 

OK,I LOOK TO FIND A LOAD TO GO HOME TO FIX THIS PROBLEM.

 

Now iam on a load to MD after when I do the Delivery,I look for a load to go back to my Home (Miami) and fix the Problem with the Oil

 

I was doing today a oilchange and the mechanic was looking the coolant,for this I known the Problem. I drive to MD Finished the run and after I drive Home to fix my Problem.I don't know how long I have this Problem. When I was doing my last oilchange everything was ok.I hope I can drive home without Troubles engine runs nice.