Weird siren noise

Not getting much traction in the Issues forum, so I'm trying again here.

This noise started recently and suddenly. Seems most pronounced after cold start and under light, pre-boost throttle (shifts back to regular turbo noise when boost comes on). I had my wife help me rev the engine, and the noise does seem to be coming from the turbo. So far I've checked the outlet connection, both connections for the UPR catch cav adapter at the inlet, the DV+ connection and assembly bolts all right and secure. I removed the recirc tube to see if it was maybe just a weird DV+ noise (didn't change). I also checked the impeller for shaft play (none observed).

It seems to be getting more consistent and maybe even a bit louder. Any other ideas?

Sounds like pretty normal turbo noise to me.

Watch the boost gauge-you can see how hard the turbo is working. If you're not PP, turn on the boost gauge in the gauge menu

I've noticed in my own cars (second Ecoboost I've owned), as the car ages, you get a little more turbo noise.

It's a very different tone that began like a switch was flipped. Hard to get on video. When the turbo starts making boost, it shifts back to the regular turbo sound, so this is only under pre-boost conditions. Everything seems to be working fine, otherwise, but something has definitely changed.

I've started getting a similar noise, starting to think I was going crazy. Not sure what is the cause.

I thought I had it figured out... the ATM hot side charge pipe lacks the resonator the factory pipe has, so that must be it... nope. :frusty: Reinstalled the factory pipe today -- no change.

Thanks to Dave at ATM for the tip on the hose removal tool. It worked beautifully.

aftermarket cold air intake and/or cold side pipe?...


....my Roush CAI will make weird resonance and noises when the turbo is spooling but no boost on the boost gauge. Something to do with the turbo making boost but the computer is keeping the throttle blade closed

Elgyn said:

aftermarket cold air intake and/or cold side pipe?...


....my Roush CAI will make weird resonance and noises when the turbo is spooling but no boost on the boost gauge. Something to do with the turbo making boost but the computer is keeping the throttle blade closed

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Both - ATM pipes and Airaid tube/factory box... but I've put both back to stock, now, and neither made a difference.

Could it possibly be the panel filter? I can't imagine how it could be, but I'm running out of ideas. All I have left are "it just sounds that way now" and the shaft bearing.

RubyRed15 said:

All I have left are "it just sounds that way now" and the shaft bearing.

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I'm assuming your car is out of warranty, but have you checked with your dealer to see if anyone else has reported similar issues?

TorqueMan said:

I'm assuming your car is out of warranty, but have you checked with your dealer to see if anyone else has reported similar issues?

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I still have warranty, but I'm not wasting time with my local dealers. They'll just blame the mods and close the hood.

My 86 SVO makes the same exact noise when cold, it's the turbo.

Is it a harmless resonance or something else, you think?

RubyRed15 said:

I still have warranty, but I'm not wasting time with my local dealers. They'll just blame the mods and close the hood.

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Lazy and/or ignorant techs. I'd take it to another dealer. One that deals with more high performance and modified vehicles

RubyRed15 said:

Is it a harmless resonance or something else, you think?

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It doesn't seem to affect the way the car drives, once the car warms up the sound goes away, and it's not there under boost. Not saying there isn't anything wrong with yours, just passing along info.

UPDATE: The siren noise was a failing turbo bearing. After hearing the turbine blades zipping against the inside of the housing, I pulled the intake off and felt obvious radial play. Turbo replaced at 27kmi.