Uplander hesitates while driving on highway?

Hey peeps thanks in advance for any helpful advice! My 2006 Chevy uplander is riding a little rough. Not while accelerating but while i am driving on the highway or speeds over 45. It hesitates or skips my rpm gauge dips for a second then fine. this tends to happen ever 15 to 30 seconds. I thought it may be the fuel filter but because the filter is in the tank its hard to know. Before i take to a shop i wanted to know if you all have any ideas for me. thx!!!

As a diagnoses suggestion, start its engine, let idle, lift its hood and with a simply garden hose with sprinkle spray, put water all over the engine. Move slowly. Actually, it's best to perform this diagnoses trick at dark time - to see any micro sparks / electrical arching. If the engine suddenly hesitates, displays some sparks or stalls, you found the problem area. If wondering, my previous Safari van did the same thing. re: It would run rough - like it had bad gas. Did the water sprinkler trick at dark time and the mechanic discovered bad spark plug wires. Note: Don't spray water directly into vented alternator unit or other extreme sensitive electronic areas. Only need to lightly spray water - to see if idling engine RPM / behaviour changes.

Hope this helps...