Around 1000 miles into owning my 18 crewcab, the truck developed a pretty severe rattle underneath the truck behind the front skid plate. It does it at specific times, mainly in drive but also in reverse, but either stopped or lightly accelerating. If I'm stopped and it is rattling, the rattling will go away if I put the truck in park. It is loud enough in drive thru's that I need to turn the truck off. The dealer has heard it, but could not replicate it while it was in their shop, so they are frustrated with not being able to track it down.
I have gone underneath the truck with it in drive and my wife holding down the brake. Not the safest thing to do, but I felt the need to investigate. It seems like the rattle may be coming from the downpipes just as they turn and go horizontal. It also may be coming from the small, S shaped skid plate behind the main skid plate on the drivers side.
I don't believe it is coming from the waste gate. It has never done the rattle at start up, or in park, only when driving or stopped with the truck in drive. 2H, 4A and 4H all produce the same noise.
Any ideas? Truck sounds like it is falling apart!
*Edit, just to note, the rattle began before the install of my Borla Exhaust and Whipple Stage 1 Kit. Neither modification has made any difference in the noise.
