Ford Techs--7.3 Ford super duty Diesel smell

[FED 387]

2000 F250 Super duty diesel---Just lately started smelling diesel (by the engine)after I shut the truck off---Maybe for an hour then it goes away--No leaks -nothing on the ground, engine is dry ,no leaks at the fuel filter---Any ideas where to look??? OR why this is happening---Have owned the truck since new has about 95,000 miles on it---I service this thing regularly oil & filter every 5000 mi--Air filter and fuel filters every other oil change---Runs great just started to smell in the last 6 weeks Thanx Comp 387