So I have a 2000 F350 with 362k miles on it. I'm getting a loud high pitched whistle sound when I hit about 2.2k revs and I know it's not normal turbo sounds. If I remain on the accelerator, the high pitched whistle goes away and a lower pitched whistling sound starts that sounds like it's coming from lower down in the engine compartment if that makes sense. The weird thing is, it's almost like it comes and goes - although it does it now almost 100% of the time I hit over 2.2k revs. I've had periods of a few days where it wouldn't make a sound but it will normally come back. Tomorrow, I plan to take a video to hopefully aid in identifying the problem. My buddy is a mechanic and he drove it and had no idea what it was, all he could tell me is that it doesn't sound too good. I sprayed some penetrating oil into the waste gate because another mechanic told me it can sometimes stick. That didn't do anything. I'm pretty puzzled about this whole situation.
Anywho, I'm gonna take it to a diesel shop when I'm off work and see what they say. I'm worried it may be something serious with the engine, or if it's some problem with the turbo. Has anyway ever heard of this? Any advice on what steps I should take to getting this fixed is much appreciated. As I said, I'll get a video of the sounds so you guys can hear it.