Twice now I have noticed that the turbo whine cannot be heard for the first 5-10 minutes of operation in cold weather. Then, at some point the turbo begins to spool up, and from then on, it sounds like normal.

It's as if the engine controller does not allow the turbo to operate when the engine is cold. Does that sound right? Can anyone confirm that the engine controller will behave this way?

thanks.....

if its an LLY then its probably because of the variable vains on the turbo. Mine does the same thing, from what I have read on this site its normal behavior for the new turbos.

The turbo basically closes itself to warm the engine faster. It's normal and a good thing, it helps a lot with warmup compared to the older motors. If you listen near the exhaust when it's cold and when it's not you'll notice the change in pitch.

The turbo basically closes itself to warm the engine faster. It's normal and a good thing, it helps a lot with warmup compared to the older motors. If you listen near the exhaust when it's cold and when it's not you'll notice the change in pitch.

Are you sure about this. When my high idle kicks in I swear I can hear the turbo a little. Is it something else that I'm hearing?:confused:

_nar_ is correct. The turbo vanes are positioned to help speed up the warm-up of the engine.

I'm sure it doesn't close all the way, just partway... Mine whistles a little on high idle too, just not near as much as when it's warmed up and totally open.