I have a 2003 Dodge Ram 2500 4x4 pickup with a 5.9l diesel and 48re trans, bought it used in January with 162,000 miles on it. recently it started making a fluctuating droning noise that is heard through the exhaust while cruising at speeds between 50 and 65 mph. It tends to disappear if power is added and then returns. Anyone have any thoughts as to a possible cause?

Does the truck have a stock exhaust system, I had a similar noise in a 97 Ram Van and it turned out to be the rear muffler/resonator. There was a TSB on it and the dealer replaced the whole system from the cat back and it was gone. Maybe it's time for an exhaust, if so up grade to a 4" SS or anodized aluminum system and let her breath!Don

the truck has an AFE stage 2, Banks High Ram intake horn and a 5" aluminized Silver-line system from the turbo back. checked all hangers, clamps etc. no visible issues. Also has a more pronounced rattle in engine.

My 05 did a similar thing, It was the rear u-joint howling.