i'm new to the powerstroke thing. bought a 08 6.4 with 59k on it. ive had it about 4 weeks now and last night i pulled up and left the truck run with the high beams and the heat on. went to move it and it was making like a turbo fart noise sorta, opened the hood and it sounded like it was in they area of the the top alternator, pressed on the back of it and it quieted it down, drove it around later and it did the same thing but wouldnt go away after pushing on it again, dealer said it was the belt tensioner at first and that the bearings are known to go bad in them but in this case it was the spring? now they say its the bearings in the top alternator went bad and its going to have to be replaced? anyone have this problem?