Tapping/rotating noise just under 2000 rpms

Almost sounds like a heat sheild is loose...
 

Brought it to dealer they said they “couldn’t replicate noise” any help? Think my dealer is lying to me honestly. Attached the video in link above
If you coast down from say 40mph to 20mph, off the throttle, so the engine is just going from 1500-2000 rpm down to 1000, do you hear it then? I get what sounds like a faint version of this, almost like trilling your tongue against the roof of your mouth.

It stops when revs dip to around 1000 rpm, or with any touch of the throttle, and is quiet enough it's proven difficult to capture on video. Below are two clips I took earlier this year, but you'll probably need them cranked up with headphones to hear it:


 
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If you coast down from say 40mph to 20mph, off the throttle, so the engine is just going from 1500-2000 rpm down to 1000, do you hear it then? I get what sounds like a faint version of this, almost like trilling your tongue against the roof of your mouth.

It stops when revs dip to around 1000 rpm, or with any touch of the throttle, and is quiet enough it's proven difficult to capture on video. Below are two clips I took earlier this year, but you'll probably need them cranked up with headphones to hear it:


Yes I do hear it than aswell
 
Yes I do hear it than aswell
Ok I tried revving in neutral and it sounds more like yours. The difference is I have to rev it up around 2000 and let off the throttle quickly, which makes me think maybe it's some kind of flutter in the bypass valves or wastegate flapper.

When I hear it while driving, it's generally when I'm completely off the throttle, and revs are coasting down from say 16-1700 to 1000 rpm where it stops completely. Touching the throttle also stops it.


 
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From interior to exterior to high performance - everything you need for your Stinger awaits you...
Update: tried to wiggle the passenger side wastegate rod with the car off and it wouldn't budge. I may try again with the car running, or maybe try to get a camera down there while revving, but the driver's side one is pretty well buried under AC, coolant, and oil lines.

I'm also not sure what the logic is for our wastegate actuators (I think the BMWs & VWs that had similar issues were vacuum-controlled, not electronic). My noise only happens at low/no throttle and low revs, and stops when I touch the throttle, so I wonder whether the WG actuators are inactive/slack under those conditions...and whether the JB4 EWGs would apply a preload there.

Anyone have any thoughts? I could be way off base here.
 
@DameFrl @LordKOTL I experimented today and am 90% sure it's the wastegate rattle that BMWs, VWs, and apparently a bunch of Ford EcoBoosts have. In VW's case somebody made a metal clip that restricts slack in the wastegate linkage, but the Ford guys went even simpler with a $4.95 pair of springs from Lowe's:

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I used paracord to cinch the wastegate linkages to nearby hard points away from anything moving (strut brace above passenger turbo, anti-roll bar below driver turbo). Obviously the material isn't ideal near a hot turbo long term, but I figured if it snagged on something it would be the only casualty (something stiffer like wire would've been much easier to route, but potentially bad if snagged).

I say 90% sure because when I blipped the throttle to 2k and let off in neutral, I still got some vibration noise, likely due to give in the paracord, but on my test drive I didn't hear it coasting down at any speed. I'll try to install the springs tomorrow, confirm the length, and grab pictures.

Passenger side, next to wheel. Directly below the two coolant line hex bolts you can see the U bend to the left (what I dropped the paracord behind) and actuator rod to the right.
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Driver side, facing up and rearward. Gold/orange bit in center lower third is the wastegate pivot, and coming off that you can see a short rod and the U bend directly below the electrical connector. Took some creativity to get the paracord up and over the linkage (couldn't find my springy claw tool).

I put a small bend & hook in a piece of wire, fished it over the linkage (orange, second picture), then used a screwdriver to lift a loop of paracord onto the hook in the wire before pulling over and back down. Took a few tries and probably 20 minutes.

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Follow-up: definitely wastegate rattle, for me mostly driver's side, and while there are probably better springs to use (due to the cramped engine bay), I got both in place, confirmed the WGs moved freely at startup (you can force the latch closed to remote start with hood open) and so far no more rattle. The springs would probably work unmodified the way the Ford EcoBoost guys use them, I just couldn't reach the wastegate linkages or oil lines.

Extra long needle nose pliers would be helpful (took a bit of work with normal ones). I modified the spring ends by straightening the last coil and reshaping the hooks. In the picture below, the stock spring is on the right, the bottom of the left spring is the wider gap needed to slip over the wastegate linkage, and the top of the left spring has been radiused to fit the bigger coolant line.

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If I'd removed the heat shield I might've been able to reach the wastegate linkage directly to manipulate the stock spring over it, but I was worried I'd never get that bottom screw back in (gap is very tight). No idea if I could've reached the oil line underneath.

IMG20241220133827.webp

For the driver's side, the turbo may be more accessible from behind the tire under the second splash cover, but I had the car up on ramps and stubbornly went from the front which meant I couldn't get my hand near the wastegate. I modified the spring, threaded it up to the linkage with needle nose pliers, and had a string tied to the other end to pull once I hooked it.

A shorter spring could attach to the upper bend on the AC line (behind the midpoint of the spring in my picture), but the spring I got was too long and hooking lower on the AC line will just slip around the bend. Instead I used that ear on the AC compressor. After the picture I reshaped the hook end to make it more secure...might eventually slip but it survived a spirited test drive.

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If you coast down from say 40mph to 20mph, off the throttle, so the engine is just going from 1500-2000 rpm down to 1000, do you hear it then? I get what sounds like a faint version of this, almost like trilling your tongue against the roof of your mouth.

It stops when revs dip to around 1000 rpm, or with any touch of the throttle, and is quiet enough it's proven difficult to capture on video. Below are two clips I took earlier this year, but you'll probably need them cranked up with headphones to hear it:
hello people, sorry to interrupt but reading this thread I couldn't resist to hop in. I have same exact conditions as I'm quoting the text. But my noise is completely different. It's like some actor making a thinking noise "hhhmmmmmm" or like hybrid car driving noises. any idea what it might be would be helpful. Here's my thread for it strange noise when rpm is dropping
 
I have same exact conditions as I'm quoting the text. But my noise is completely different
The noise I'd hear from inside the car sounded like when you trill your tongue against the roof of your mouth, or a card in the spokes of a bike wheel, which didn't strike me as metallic at first. Only when I'd rev in neutral and let off did I get the more metallic vibration that the Ford, BMW, and VW guys have.

Your other post and the catalyst errors make it seem like something different, but if you can get a clip of the sound we can take a listen. You could try tying something around the wastegate linkage to test that (you want it snug enough to take any slack out, but not so tight the actuator can't move it).

If it is clogged cats as someone in the other thread suggested, you could check the secondary ones first, and then if you don't want to risk breaking studs on the primaries, you could try hollowing out the primaries with them on the car. They obviously won't function as intended, but if you think they're already shot...
 
From interior to exterior to high performance - everything you need for your Stinger awaits you...
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