2001 Ford E350 Passenger Van
 

Wife started up yesterday and the van sounded loud and chattery and maybe a little backfire. Recently serviced. In a quick listen and look seems possibly in the carb. This is a V10 engine. Anyone have suggestion before I call a mechanic.

A little FYI may be in order.
Your vehicle's engine is fuel injected and that system is computer controlled by various inputs and sensors .
Not knowing where and who serviced the engine, but those engines are very dependent upon the proper grade and kind of oil used.
Did any kind of notice appear like a check engine light? It is just about impossible to offer any worthwhile suggestions as to what the problem might be without being there to see and hear the noise it is producing. There are things called cam phasers and chain tensioners that might be malfunctioning. You will most likely need to have someone experienced take a look at it. At this point it could be almost anything and wish we could be more helpful.