Can you please give more details. Like is it making it during driving, or at idle etc etc. Post a video if possible.
I already provided videos to the dealership, but I don't have them right on me to upload from work. It's as I described, though: it sounds like a police siren, but since it's low volume, it would at first seem like it's a police siren in the distance. I'm very hypersensitive to sounds, but since I'm somewhat experienced, I can also tell when something isn't normal. It's most pronounced on a cold start as the engine RPMs are up and the turbos spool, and it is also there when under light acceleration between 20-30 MPH.
Typically failing turbos give a 'dentist drill' sound when trying to make boost.
It's lower tone, and that could be down to the configuration (size, compression ratio, etc.) of the turbo, but it's definitely a police siren pitch for me.
I think the siren sound is made if one of the blades gets chipped or broken (happened to me on a previous Alfa turbo). I guess likely cause of breaking a blade will be if the bearings or shaft are allowing excessive movement?
Would definitely get the turbo changed quickly before it disintegrates and destroys the motor.
I hate to say something like this outloud on a forum, but I DID poke around down there, and found two small pieces of metal sitting at the bottom of the intake tubing pre-turbo (which I promptly removed). The car is already at the dealership, but as I commonly have to deal with, they treat me like I'm an idiot even though I'm wholly more capable than their technicians when I was explaining the noise, what it means, and how there have been other Stinger GTs with failed driver's side turbos. It's a good thing I came with video evidence, because they were telling me it'll be two weeks (from Fri when I called, telling me their next open date is Oct 9th) before they can look at it, and then after the videos they said end of this week because "they're booked up". I explained the hell out of them how a blown turbo could mean much worse on them to work on and that it needs to be at their dealership ASAP, so pretty much forced them to take my car and it has been sitting at their dealership doing nothing, probably getting dirty and going to end up with new dents until they get to it
. The service advisor was revving my car in the service lanes trying to "replicate" it, and I was about to smack that dumb f****r but also hoping it would blow right there just so I could laugh at him for not knowing his shit about what catastrophic failure could happen if that turbo blows. Of course, in idle, the car does not build much boost unless revved really hard, so of course it didn't make enough noises...
I think these modern day mechanics don't understand how to diagnose, they only know how to follow a computer on how to fix something. I feel like they're just going to struggle to "replicate" it simply because the turbo hasn't actually blown and thrown metal into my engine. I really hope one of them, just one, has the wits about him to follow the clearly outlined conditions in which to replicate the sound so that he will have to investigate it and check out the turbo.
But it's definitely coming from the driver's side turbo as I had listened to it several times myself in the mornings before making that call into the stealership.
