I have experienced on some cooler mornings (35-50 deg) a loud, high pitched wine when first starting out and quitting withina 0.5 mile of home. Is it the turbo getting oil/warmed up? Any Ideas?

Mine does it too. Only does it for about the first mile or two if I don't let the truck warm-up too much prior to taking off. To me it sounds like a very high pitched "whistle" as though air is being diverted somewhere because you can tell when it stops - as though a sensor kicks in and changes airflow.

Much different than the normal Trans. whine from the rear end when it's cold.

Can you say VVT?....:rolleyes:

Your LLY engine has a Variable Vane Turbo installed on it and no waste gate like the LB7's to control turbo pressure output.

So when your engine is cold, the VVT moves toward a more closed position in order to help warm up the engine. In fact if you really want to hear it, in cold weather with the high idle engaged, the VVT will move to it's most closed position and EGR gasses will be recycled through the engine to warm things up, you can really hear the turbo then.

As the engine warms up or you drive off, the VVT opens up to a more normal setting and the noise decreases, it's all quite normal...;)

Thanks for that explanation on that noise. On my '05, when its cold I hear an intermittent howl more than a whistling sound. Seems to go away after a few minutes.

Mine sounds like a jet engine and I love it! I wish it sounded like that all the time.

Thanks for that explanation on that noise. On my '05, when its cold I hear an intermittent howl more than a whistling sound. Seems to go away after a few minutes.

Might be the Fan clutch but I'm not sure since you said the howl is intermittent.

I've heard the fan clutch noise (roar) before which is much different. This noise is a howl for lack of a better word. My ears are not what they used to be, but this morning when I heard the noise it seemed to be coming from behind me. I just put on a Leer camper top and I'm wondering if that has created an echo chamber of sorts in the bed of the truck. Maybe the noise is related to something in the rear of the truck; driveline, exhaust, that is resonating.

Mine does the fan clutch roar when it's cold for about 1/2 block.

What Axle describes seems more like fan clutch than turbo noise. . . hard to say for sure without more details.

Dennis