I originally went to the dealer for a check on what I thought to be a rough idle. They changed the filter under recall and that was that. Idle problem was still there. Then I noticed smell of unburned diesel coming from around the engine compartment. Took it back . Dealer found injector failure and replace all of them. The truck seems very powerfull and smooth. Not for long. Now I have a clattering unlike the normal deisel sound under load. Truck seems louder under hood period! Should I try dealer again or is this normal?