I was pulling hard above 6k or so and herd a odd sound. It really sounded like something hitting metal fan blades or maybe a sounded like the flywheel ring gear at the gears hitting something. Well I don't have any metal fan blades maybe the alternator but its not hitting anything I can see. I herd it 3 times in the above conductions. I looked close at the moving parts and nothing is hitting anything or even close. My engine doesn't move much at all. I have a soled diff brace and a rubberized trans mount. My engine mounts are in great shape. It does not sound like a heat shield at least not your normal shield tone. It sounded from the driver seat like I could here it in the front fender well area, I assume its just passing there and coming from the engine compartment. I know what it sounds like in a piston engine but this was different. The sound was not balanced/symmetrical the tones/sounds/pings were there for a second maybe three or four unequal tinging bursts. Any thoughts??????