Yeah i know it does't make sense but hear me out. I replaced the thermostat the other day on my 06 Voyager 2.8 and let me tell you guys i'm no newbie and stranger of working on engines , but changing that thing is/was a nightmare and i will never do another one i swear. Anyhow, to undo the bolts of the thermostat required pushing and shoving aside the air intake duct/pipe(see attached pic), and got so bad on my nerves that at one point i had to force-push it under the firewall just to get some more space. Stat done all fine and dandy, took the van for a spin about 100 miles around trip and i heard very high pitched whistling sound coming from the turbo, every time i gun it thru the gears i hear it loud, cruising speed it's there but less notable.
So my questions to you guys is> Is it possible me pushing the air intake hard i dislodge it from the the turbo, and hence the high pitched noise?, and if that's the case i overspin the turbo? My experience on the second question tells me no, turbo can and will be overspin if there is sudden drop of pressure, but what do i know...Thats why i would like to hear your expertise in the matter and will greatly appreciate it.

Thanks in advance John.

 

You could have dislodged the pipe slightly or maybe created a split after forcing it. I would take the pipe off and check it just to be sure.

 

Yeah Royal that's what i did but had to lift the van on the lift.Problem solved.... the air intake was dislodged from the turbo.All back to normal.

 

I've heard someone say it whistles because its working right in another forum. Truth is there a leak somewhere.
Here's something for you. If you've ever heard an HST power car, with its V12 Paxman engine whistling when its going some, its because the tips of the turbo vanes are going through the sound barrier.

 

Goggs, the turbo works, i felt no power lost or anything like that,the whistling was from the turbo intake sucking air from half dislodged pipe/duct.And yes it does whistle it's a turbine after all, but it's much more quiet now. Hopefully it did't sucked in too much dirt and ruin it.

 

That's right you got it...