I have noticed that when I am either accelerating or at about 3/4 throttle and abruptly let off the gas, there is either a air suction sound or some sort of fuel starvation sound that comes from the engine. It does not do this if I let off the gas slowly. what could it be

 

commonly reffered to as "turbo fart". they all do it.especially if youve got an aftermarket intake.when you let off the throttle quickly the turbo boost has no where to go, so it tries to come back through the intake and tries to exit through the turbo.

 

thanks man.

 

I always thought that they had a dump valve.

 

no wastegate on a vgt turbo.the unison ring on the exhaust side of the turbo does the job of it, just not as well.

 

Wastegate that's what it's called....Thanks.

 

I thought the waste gate is what controlled the amount of boost and a pop-off/blow-off valve released the pressure? But then I don't really know what I am talking about

B.

 

You can hear it really well in this video:

YouTube - 6.0L Powerstroke SCT Tuned "Turbo Fart"