1999 QC 24V 3500 dually 4x4 stock except a edge ez.
ok, not sure how to explain the sound that the turbo makes other then this.

when i am accelerating hard and just let off the pedal sometimes i instead of a good blow off sound that we all know it almost sounds like it skips or echos. kind of like fa fa fa fa fa fa fa. told you that sounded stupid but didn know how else to explain...... any help would be greatly appreciated.

 

Have You Checked The Compressor Wheel For Damaged Vanes Or Bad Bearings?

 

Its called Turbo Bark...I would not do a very good job of explaining, but if you do a search for it, you'll get a better idea of what it is and why it happens.


Scott

 

As STate has mentioned, that is what we recall as Turbo Bark.

Since you are running the engine hard and under load you have a fairly high amount of boost going through the air to air system. When you let off the throttle quickly you are cutting back fuel, which in turn cuts back RPM. All of that pressurized air that is in the system isn't fed into the engine fast enough, so it looks for another path. Which is heading back towards the turbo and out the air filter. This is very hard on turbo's because your turbo is spinning one direction at xx,xxx RPM and that air wants to push the compressor turbine the other way.