So it doesn't seem to be bothering anything but there is just a high pitch noise that annoys the crap outta me and it usually only happens between 20-45mph. and normally only in the higher rpms(2700-3300). i know it's not my turbo duh. but i'm not quite sure what it is. it sounds like air goin through a tight space maybe. or kinda like when you whistle with a piece of paper(if you know what i'm talkin about). but yeah any ideas about what it is? -

Big_Johnson's Sig:

'03 GMC 2500HD ext. cab, PPE Standard, PPE Boost Increase Valve, AutoMeter gauges, 20%tint all around.
07 New Holland TC30 Gearshift, Front End Loader, 30hp, 4wd, 60" Finishing Mower

Big Johnson

is the door shut?? -

stkdram55's Sig:

Just an Inline 6 Cylinder

Only 2 defining forces have ever offered to die for you.....Jesus Christ and the American Soldier..
One died for your soul, the other for your freedom.

My guess is turbo whistle.. it can be deceiving. -

Oilfield_Mafia's Sig:

>> Become a BOMBARDIER Today! <<

_____________________________________

07 Classic LBZ CC/SB 4x4

TransGo Jr, 4" MBRP,6" Single Mitre Cut Stack, Autometers in Pillar

Blocked, Custom Cold Air Intake, Resonator Delete

PPE

Big Thanks to Jim @ Upstate Diesel, Gasuout, 2500HeavyDuty, RSWORDS & Everyone else here @ DieselBombers.com

Sounds like a turbo whistle to me too. Check everything on the intake and exhaust that you've jacked with. On the exhause side, just look for black soot marks to find the leak.

A known problem with the LB7 is a rub through on the dr boost tube. Check the dr boost tube, down low. It makes contact with the power steering return line and wears a hole in the boost tube. You may need to remove the tube to inspect it, because it wears on the bottom side. I'll try and find a picture for you. -

Rttoys's Sig:

'05 Chevrolet CC/SB Duramax/Allison

I say turbo whistle too......tighten every boot

yer gonna laugh at this but I have seen it many many times...................when the fog is thick and making lotsa frost....it builds up on yer radio antenna and whistles like crazy....very high very schrill whistle....pull over and knock the frost off the antenna and it quits.....serious man its weird -

Whit's Sig:

* 01 Cummins/Dodge/HO/6 speed*275 injectors*PDR 35 turbo w/14cm housing & high pressure boots*HTT 3 piece ported exhaust manifold*Progaurd 7 with prefilter*Edge Comp*Fass II*Southbend con OFE*Jacobs brake*5"Stacks Big ens*E/F shift knob w/2low & brake switch*10 Gages*KW Ram air System cab controlled*Rickson 19.5x265's*True speed calibrator*Rancho 9000's*DT track bar*DSS steering stabilizer*KW Side impact rails*KW Traction Bars*Toolbox/fueltank 60 gal Combo*Mag High Tech Diff Cover*Ranchand bumpers*Grover air horns*Rear Wheel Cylinder Upgrade DYNO 375 Horse 941 Torque

Always remember...when life hands you Lemons,ask for Tequila and Salt and call me over!

You need to lay off the sauce Whit.... -

lmao. yeah it's definately not frost on my antenna. but i will check all my boots. i thought i had already but i just remembered one that i missed. so i'll go check it out and see if that fixes it. -

windows all the way up?

-

2500HeavyDuty's Sig:

The Original LB7
EFI LIVE, Suncoast IV, AirDog, Banks Intake, Mbrp Exhaust, Ranch hand bumper replacements, H2 wheels with 35's, and some secret squirrel stuff
12.9 @ 103

yes the windows are all the way up.
however the passenger window was making an annoying sound the other day but it's fine now. -