I've been getting closer to locating the idle vibration/ moaning while moving problem I've written about on the forums several times. When it's cold outside and my truck goes into automatic fast idle I can hear a sound like someone blowing over the top of a bottle coming from the engine compartment. Also, at regular idle speed there is a constant hum/vibration coming from behind the dash. It's not the exhaust. I disconnected the exhaust from the truck entirely and the noise is still there. I just installed a 4" exhaust and it didn't cure anything. So I found a way to duplicate the "blowing over the bottle" sound and I found a new vibration: I just did the 'high-idle' mod. The other day I put the truck into high-idle, and notice the "bottle" sound return. I got out, popped the hood...and lo and behold, I could hear the "bottle" sound coming out of the engine compartment...I listened closer...It's coming from the turbo! I put my hand on the intake side of the turbo: it's vibrating at high frequency...the intake boot that attaches to the pipe going from the turbo to the intercooler is buzzing like hell! When I put my hand on it, it was buzzing as a bad as a massager???...so, I turn OFF the fast idle...'bottle' sound gone, turbo/boot stop buzzing...as far as I know, no part of the turbo should ever vibrate or buzz like that...turn the fast -idle back on...it's back! I am now convinced that my idle vibration and the moan while driving is turbo related...but when I took it to the dealer the tech claimed the truck was fine and wouldn't mess with it cause it wasn't throwing a code...could the turbo bearings be about to go??? I think maybe I should try another dealer and see if they'll help me?