When driving down the road around 45 mph and up, it sounds like a typical "exhaust leak" sound coming from the driver's side and comes with acceleration. I have had it in the dealership twice for this and they can't locate anything. The other odd thing is it comes and goes. Sometimes when I hit a bump in the road it will come or go OR if the road has "waves", it will go from faint to louder to going away with the waves.

My buddy has the same truck as I do and it does the same thing. Is this normal or where should I (we) start looking? We haven't been able to locate soot deposits anywhere.

And no, it's not the turbo whistle.

I would check the intercooler rubber hose connectors. I had one there on my LMM on the one up near the firewall on top. Had dealer repair and the one sound i heard is no longer there now.

Brian