2016 3.5 Ecoboost "Woosh" of air when letting off throttle

[RichardSlay]

I picked up a 2016 Explorer Sport from Carmax about a week ago. Today I noticed a new sound. When accelerating moderately or aggressively and then letting off the throttle I hear a "woosh" of air. Kinda like when you let air out of a balloon. It only lasts about a half second. I'm guessing its the turbo waste gates. It does not make the sound when just revving the engine in the driveway. Do they have "exhaust" hoses to route the air away from the engine when they open? Fortunately I have a warranty with Carmax so I'll be taking it to them for that and a couple of other issues I've found. Just wondering if anyone had any ideas. Car has 116K miles with the 3.5 ecoboost.

 

[mguy13sport]

The Ecoboost use an air diverter valve that recirculates turbo air back into the intake so from the factory it should be quiet. There is no blow off valve but you can buy aftermarket adapters that bypass the recirculation (Boomba makes these). There is more than likely a boost leak or wastegate not operating properly.

 

[Odrapnew]

As @mguy13sport said, it’s likely just the bypass valve, but they are virtually inaudible in factory form.
Did this just start, or is it possible you just noticed it?
You likely won’t hear much when free revving it because you won’t build much (if any) boost.

A few things to check.

Do you have an air filter installed? If someone removed it, you’d hear a bit more of the intake noise.

It’s possible someone did a mod to vent the bypass to atmosphere. If you pull the upper cover off and look on the driver’s side near the air filter, you should be able to see the bypass valve and see if it still has the hose to the intake.

Some pictures in this thread.

How to: - Explorer Sport EB convert to vent to atmosphere with factory blow off valves

What does this mod do for you? Nothing but making a PFFFFT noise when you lift the throttle under boost. Is there any downsides to this? No, the car is speed desnsity so releasing the air from the turbos to atmosphere when the blow off valves open does not negatively impact the tune, factory...

www.explorerforum.com

 

[RichardSlay]

This sound just started yesterday afternoon. It happens even under light/moderate acceleration. It does have an air filter and the bypass valve hose is still installed.

 

[Odrapnew]

This sound just started yesterday afternoon. It happens even under light/moderate acceleration. It does have an air filter and the bypass valve hose is still installed.

It's not uncommon for the intake hoses to pop off connection points due to loose hose clamps and the boost pressure.

Do you notice any reduced power?

 

[RichardSlay]

It's not uncommon for the intake hoses to pop off connection points due to loose hose clamps and the boost pressure.

Do you notice any reduced power?

No, seemed to continue running strong.