General Prevalent turbo flutter in b58?

[HereinDaRockies]

I don’t know if this is normal, or if my vehicle had always behaved like this, or if this is a recent change in behavior. I have definitely noticed it more in recent weeks. It relates the audible and prevalent turbo flutter sound.

Vehicle has 2000 miles on it.

Symptom:
With the radio off. While I am driving on neighborhood streets - less than 20mph. If I accelerate gently (rpm under 2k) then let off the accelerator completely, there would be a very notable turbo flutter (a throaty whoosh) sound from the passenger side.

I can make out this sound with windows closed. With windows open, the sound is more pronounced obviously.

I feels like I haven’t noticed this in the past. Perhaps it’s always there and this is normal b58 turbo behavior.

Thoughts?

Sound attached below.. you will hear gentle acceleration followed by the whoosh..

 

[MurphyMurph]

It’s normal. Do you have the raised air intake? It’s more pronounced with that. I like the sound. Makes maneuvering at low speeds eventful.

 

[Dlucky]

I don’t know if this is normal, or if my vehicle had always behaved like this, or if this is a recent change in behavior. I have definitely noticed it more in recent weeks. It relates the audible and prevalent turbo flutter sound.

Vehicle has 2000 miles on it.

Symptom:
With the radio off. While I am driving on neighborhood streets - less than 20mph. If I accelerate gently (rpm under 2k) then let off the accelerator completely, there would be a very notable turbo flutter (a throaty whoosh) sound from the passenger side.

I can make out this sound with windows closed. With windows open, the sound is more pronounced obviously.

I feels like I haven’t noticed this in the past. Perhaps it’s always there and this is normal b58 turbo behavior.

Thoughts?

Sound attached below.. you will hear gentle acceleration followed by the whoosh..

View attachment 7885309

Mine makes that noise too. I’d say normal

 

[anand]

Absolutely normal. There are a couple factors at play here.

As @MurphyMurph stated, it is much more pronounced with the RAI, due to the hard plastics offering a resonance and piping it "up".

One reason you'll hear the "flutter" more on our vehicles is because the B58 doesn't utilize a bypass valve (diverter valve, pop off valve, recirculation valve, whatever OEM terminology you'd like to use) like the vast majority of turbo petrol vehicles use. This is what normally gives you a "Pshh" sound when you let off the throttle in a turbo petrol vehicle. Instead it alters the valve timing to allow the (now unused) boost pressure through the cylinder head and out through the exhaust manifold instead of stalling the turbo.

The latest (mild hybrid) B58 does have a bypass valve, but that is specifically because of the way the cylinder "deactivation" works on that engine