2017 Expedition P0299 and whistle

[Mphomes1]

Over the weekend while out of town, the expedition started a high-pitched whistle. As the weekend went on, the whistle got louder. And on the three hour trip home, it started to become sluggish. Doing my research on the Internet, said that it was a boost leak either from the eco-boost pressure relief valve having a ripped diaphragm or one of the pipes has a leak. I’ve taken off the pressure, relief valve and inspected it visually and it appears to be normal and the plunger operating normally. I cannot find any cracks or problems with the pipes either. I also re-torqued the passenger side turbo and I have had no luck. Has anyone had this problem and or can help me identify what it is? The sound seems to come from the passenger side.Here’s a recording of the sound as I rev the engine in the driveway between 2000 and 3000 RPM.

Expedition whistle.m4a

drive.google.com

Expedition whistle

 

[dkincaid32]

Have you checked your header bolts? I have a 2017 too and had broken header bolts on both sides. Mine never developed a whistle, but I've read that is a symptom as the header warps and releases exhaust. On mine I had a distinct smell.

 

[rslynes]

That really sounds like a massive leak in the air pipes somewhere. You can't always see a crack in the plastic, but you can feel it if you run your hand over the pipes.
Have you tried having someone run the accelerator whilst you're under the hood or below the engine? You might have to remove the fabric 'skid plate' to gain full access underneath.

 

[rslynes]

It could also be a failing turbo, but they're more of a whine when they start to go.