Nor_Cal_Angler

still kinda new to the world of turbos...and i have noticed a noise that has surfaced...i didnt hear it before so i would like some help possibily identifing it.

stock truck with stock turbo.....had it that way for awhile..know what that sounds like..removed sliencer ring and noticed the sound change..know what that sounds like....have it that way now....

about 3 weeks ago...i noticed a noise that isnt what i was used to....it only happens after driving the truck awhile and happens after the engine has warmed up....it doesnt happend under throttle...only seems to happen when i have let off the throttle...it is a audible pitch change, different than the sound a turbo makes w/o the silencer ring...that is how i know it isnt the ring just being out....my friend said ohhh thats just the sound it makes w/o the ring in there...i said NO....i have been driving w/o the ring for a few months now and it hasnt made this noise....


you all know what a turbo w/o a ring sounds like...at idle and durring spool up...

here is the scenerio....spool up...let off the GO PEDAL...makes the normal WOOOOOSH then in comes this HIGH PITCH sound....if i tap the brakes to bring the boost back down faster the sound goes away...if i just let it idle down normally it will make the sound longer and sometimes cont. to make it untill i hit the brakes..(no its not the brakes)..it comes and goes....it has happened a few times when i pull up to the house and let it idle, while sitting in the truck i can hear it over the motor idle and exhaust....that is when i knew it wasnt the brakes.

what does this seem like to you all.....

i am wondering if it is shaft play, gunk build up, not enough oil, etc.....like i said still really new to the turbo/diesel world....

sorry for the long winded explaination..just wanted to try to describe it as best as i could.

thanks

NCA