3.5 turbo fluttering with woop woop noise

[JumboJVT]

Mine ('25, 3.5EB, 9/15 build, 3K) just did this today after reading this thread this AM. 1800 RPM upgrade, neutral throttle (neither accl or decel), revs surging 100 RPM in sync wih the whistel-ly whoop. Soon as I stepped out of it it stopped and I couldn't duplicate right then. Did it again later under same conditions. This time I stepped INTO it and it stopped. At least on my example it acts like it just doesn't know quite what to do with a light throttle after calling for a bit of boost. I'll add this to the list of things its doesn't quite know what to do (downshift, for instance) and drive it 'till it breaks: chasing phantoms in these things will waste too much of my time to do otherwise.

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[2.7EcoBoost]

Yes, sadly due to FoMoCo incompetence, I have learned to ignore it. Doing the VTA mod has greatly eliminated the sound i hear as well as making the actual surging much less pronounced.

 

[FaaWrenchBndr]

So for those of you getting this whoop whoop noise I have a question.
Have you guys done the air deflector technical service bulletin?

https://www.f150gen14.com/forum/attachments/2264-pdf.125066/

 

[JumboJVT]

So for those of you getting this whoop whoop noise I have a question.
Have you guys done the air deflector technical service bulletin?

https://www.f150gen14.com/forum/attachments/2264-pdf.125066/

Late build '25. I'd presume 2 years after this TSB was issued that it was addressed in production. And its an EB, not PB, so no issue with the deflector from the outset.

 

[FaaWrenchBndr]

Late build '25. I'd presume 2 years after this TSB was issued that it was addressed in production. And its an EB, not PB, so no issue with the deflector from the outset.

so some guys with eco-boost have had this air deflector blocking off flow as well. It’s not just a powerboost deal……it’s a 3.5 deal

does your air deflector have the cut out?

 

[2.7EcoBoost]

My truck has the cut out air deflector, so it's not that. The issue is the blow off valve, or I believe Ford calls it a turbo pressure relief valve, is doing exactly what the PCM is telling it to do. it switches open/closed repetitively when the truck is in the parameters we all mentioned. I believe most every 24 and newer 3.5 will do it. Some seem to be louder, not sure why. It's a normal characteristic that should not be normal.

 

[FaaWrenchBndr]

My truck has the cut out air deflector, so it's not that. The issue is the blow off valve, or I believe Ford calls it a turbo pressure relief valve, is doing exactly what the PCM is telling it to do. it switches open/closed repetitively when the truck is in the parameters we all mentioned. I believe most every 24 and newer 3.5 will do it. Some seem to be louder, not sure why. It's a normal characteristic that should not be normal.

I’ve never heard this sound. 24 with just over 21.5k

 

[Mt.F150..]

People pay money for the woop woop

 

[Jerome10]

I think my wastegates rattle in this type of driving condition. Hate it.

 

[RoastinF150]

I didn't read everyone's responses, but that sound, sounds like turbo surge. That means your bypass valve is probably not operating properly

 

[bwdutton]

I mostly hear this flutter sound when in the mountains/hills. The 5 second sound clip on https://www.cjponyparts.com/resourc...JOVkdfnWM21N8fT6zqMGF8fPRrgr8KE5TsrplFrtf1CxN sounds very similar to what I hear. Based on that page the dealer should check out the issue.

 

[JumboJVT]

I mostly hear this flutter sound when in the mountains/hills. The 5 second sound clip on https://www.cjponyparts.com/resourc...JOVkdfnWM21N8fT6zqMGF8fPRrgr8KE5TsrplFrtf1CxN sounds very similar to what I hear. Based on that page the dealer should check out the issue.

Mine sounds kinda similar, but at nowhere near peak boost (barely any, frankly) and it only happens a with a steady throttle, neither acel or decel, but always up grade so under some load. Added or reduced throttle will stop it immediately. So if closing or opening the throttle(body) stops it, its not the same thing discussed in the article IMHO.

 

[TheGoatman]

Time for a new air filter?

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