I seem to be having a similar problem. Everything was fine until 9800 miles then all of a sudden it started. I can here it at idle but it's most noticeable at 2600-2800 RPM's which just happens to be around 70 MPH on the highway which is what I was doing when it started (trip to FL). Dealer in FL said it sounded ok to them. When I got back the local dealer said he couldn't find anything wrong but had a factory rep coming in two weeks. The factory rep couldn't find anything wrong either. All this and they have never opened the engine. It seems if it's not in the diagnostics it's not a problem to them. The service manager told me they don't work on the engines just replace them, but, there isn't one available. Actually I would like to keep my existing engine (matching vin #'s) unless maybe they had an SRT6 engine.

Anyway really pisses me off. Not only shouldn't the car sound like the lifters are ready to fly off, but I paid for the extended warranty and what good is it doing.