turbo problems???
 

I have a 2003 4 dr kr f350..during my trip to flda and coming back I had which sounds like a turbo fart ..rupp rupp this occurred when I got into va and hilly country pulling a 5th wheel..happened about four times going down and coming back..my brother said I was kicking out black smoke from exhaust when this happened..during stay in flda no problem..drove up town today no problem..can anyone give me some insight to the problem??what should I have local ford dealer check??do you think its turbo or something else truck has 145 plus kms which is around 90000 miles or so..starts good runs except for these times like a top...can anyone out there give some insight to this problem with thanks.. Karl...update no ans yet any thoughts