Turbo "groan"

[88GT]

Hi y'all. New member, and in need of some quick help if possible.

I have an '07 350. Everything is stock under the hood. I took it in to the dealer for some seal leaks, ball joint replacement, and rear brakes.

I also reported a gear whine/groan sound. It pitches up with an increase in RPM and down with a decrease in RPM, exactly as you would expect gear noise to do. They're telling me it's the turbo and want to put in a whole new turbo. I have a couple of problems with this. First, they didn't tell me what was causing the whine/groan in the "bad" turbo. Second, the bad lower ball joints are really bad on the passenger side and I can hear the awful noise and feel it in the brake pedal, but the dealer is trying to tell me that the turbo whine/groan ramps up during turns and that's part of the noise I hear during turns.

I don't know that I buy that. Particularly since I haven't noticed any difference in the groan on left turns. And only the ball joint sound of destruction on right turns. Here is a direct quote from the dealer email:

Turbocharger is making noise, may be some of the groaning you hear on turns. Traditionally an excessively loud turbo makes noise no matter if driving straight or turning but something in the throttle to rpm ratio is creating more noise on turns.

I questioned her about identifying the cause and not just telling me it was noisy, and this is the response:

The moan could be a sign of a future failure but right now it is simply a noise associated with rpm's and generated thru the turbo.

To her credit, she suggested just monitoring for now, which given the cost of the other stuff I will probably HAVE to do. But my question is this: what would be causing the groan/whine? And why can't the dealer be any more specific about this?

I searched past threads, but aside from an EGR valve plate not being torqued down or leaks in the system, I didn't see anything that struck a chord with me as being similar based on noise/circumstances. (Granted, mechanical issues problem solving is not my forte.) At any rate, is it unrealistic to assume the tech would have done an leak test to rule that out?

When I have more time to search old threads tonight, I'm going to dig deeper, but if anybody has any ideas, thoughts, etc to share, I would appreciate it very much.

[PSDMikeB]

Sounds suspect to me, turbo RPMs and engine rpms do not always conincide. However changing noise with RPMs and noise when turning makes me think power steering pump. This also powers the brake booster.

Do you hear the groan at idle? If so, step hard on the brakes. Does the groan change? If so, you have a bad steering pump or hydro boost unit.

The Ford pumps are known to be pretty noisy.

MikeB