I have a 2001 d/a with 93,000 on it. Lately when I have been towing the boat I hear a funny whistle sound like one of those deer whistle warning things people install on their cars.

Any ideas?

Thanks,
NeilW

The Duramax emits a high-pitched turbo whine under certain conditions. Pulling a trailer tends to set up these conditions. In my truck the whine is emitted when the boost level is about 2 psi, which is where it sits when pulling our 5th wheel steady on level ground at highway speeds. If you don't have a boost gauge the condition for generating the whine is between 1500 and 1900 RPM with light throttle applied. If you move the go pedal, even slightly, the whine stops immediately. If your noise doesn't follow these characteristics I'd think it is coming from somewhere other than the turbo.

It's possible it is the charge air cooler hoses leaking.Try tightening all the band clamps on the blue hoses.It is 11mm and there are 8 total to check.Your dealer can actually check for leaks. Some pipes have worn threw rubbing on top of the power steering gear box you might look.The other spot is the outlet blue elbow from the turbo sometimes splits.

It's the TURBO. My wife HATES it.

I was kinda thinking it may be the wife whining